The Black Sea from Paleogeography to Modern Navigation: Applied Maritime Geography and Oceanography 3030887618, 9783030887612

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Romeo Bosneagu

The Black Sea from Paleogeography to Modern Navigation Applied Maritime Geography and Oceanography

The Black Sea from Paleogeography to Modern Navigation

Romeo Bosneagu

The Black Sea from Paleogeography to Modern Navigation Applied Maritime Geography and Oceanography

Romeo Bosneagu Navigation & Naval Management Faculty Mircea cel Batran Naval Academy Constanta, Constanta, Romania

Translated into English by Monica Bala and Professor Lavinia Nădrag, Ph.D. Copyright 2022. All rights reserved. No part of this book may be reprinted or reproduced in any form without permission in writing from the publishers/author. ISBN 978-3-030-88761-2 ISBN 978-3-030-88762-9 https://doi.org/10.1007/978-3-030-88762-9

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© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Abstract

Maritime lines are basic components of the economic infrastructure of the Black Sea’s coastal states. The development of maritime routes in this area was determined by the geographical and politico-economic factor. The strong development of the world economy, especially of the Western European and Mediterranean one, has recently impelled the development of the economy of the states from the Black Sea basin. The sea, an international means of communication, has become indispensable for the economic development of states, providing a cheap and large means of transport of raw materials and manufactured goods. Also, the sea is a source of wealth for the coastal states, but also for the continental states. The need to master this source has accentuated today’s global competition. Since ancient times, the Black Sea has been researched, traversed, and taken over by seafaring peoples who have built port cities on its shores, which survive to this day, the geographical factor being the main criterion in choosing the right places for them. It is therefore necessary to research carefully the geographical and historical conditions that determined the appearance of navigation and maritime transportation in the Black Sea, in order to find adequate answers to the future needs of economic and social development of the area. From the point of view of its origin, the Black Sea is an inland ingression sea and represents a rest of the Pontic Lake, detached from the Sarmatic Sea, which formed about 10 million years ago in the Miocene-Pliocene. In the Quaternary Era there were important transgressions and regressions of sea level, with large amplitudes, (the most notable regression took place in Neoeuxin, about 12,000 years ago, with a value of at least 70–80 m), as evidenced by the submarines, today clogged valleys., on the shelf in front of the Romanian coast, in the northwest of the Black Sea. At present, there is a slight rise in sea level (on an oscillating background). Relatively recent studies have established the existence of a suboceanic-type crust in the central part of the Black Sea, by thinning the basic granitic layer (continental in

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nature), as well as considerable thicknesses of the sedimentary layer, unconsolidated detritus. The elements of the Black Sea’s morphohydrography and morphodynamics analyzed in the paper reveal the following: – The Black Sea’s hydrographic network with an area of over 22 million km2 stretches over a large area of Eurasia, the contribution of fresh water and sediments being considerable (the Black Sea flows into the main rivers and streams in Europe). – The Black Sea coast is divided from a geomorphological point of view into 17 main areas with specific characteristics. – Although it is a closed sea, the Black Sea is connected to the north by the Kerch Strait with the Sea of Azov and to the south by the straits of Bosporus and Dardanelles with the Mediterranean Sea and the Atlantic Ocean (the Black Sea is considered the easternmost Mediterranean of the Atlantic Ocean). – From the point of view of the seafloor characteristics, the Black Sea is divided into two areas, one with small depths of up to 200 m in the northern part and one with depths greater than 200 m in the southern part; specific to the Black Sea is the fact that after the continental shelf (it extends to depths of 200 m), the slope of the seabed is steep, except for the northwestern sector of the sea; – The Black Sea is a deep sea with an average depth of 1,271 m and a maximum depth of 2,212 m, the level difference between the top of Elbrus (5,633 m) and the maximum depth being 7,878 m; the 100 m isobath passes almost parallel to the shore at distances of 1.5–6 nautical miles (west, northwest, and near the Kerch Strait this distance increases to 50 nautical miles, so that it is possible to navigate heavy vessels in proximity to the coast). – Although the shores of the Black Sea are relatively slightly notched, there are still favorable conditions to ensure the development of ports and the sheltering of ships against winds and storms. – The ports have developed in bays such as: Burgas, Varna, Odesa, Sukhumi, Trabzon, Samsun, Zonguldak, and others, or in the shelter of high capes or shores such as Mangalia, Constanţa, Midia, Novorossiysk, Batumi, Sinop, and Eregli. – The shape and dimensions of the Black Sea determined the length and orientation of trade routes between ports. – Given the relatively short distances in the Black Sea, of the order of tens and hundreds of miles, the transport routes, at medium average speeds, can be covered in a short time interval of hours and tens of hours. – Where the coast is high, conditions have been created for the development of a complete and efficient coastal navigation system, a situation which is less good in this respect in areas with low shores. – A special feature of the Black Sea’s coast is its permanent modification. The changes in the relief, especially in coastal areas, act as a result of:

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– The direct action of waves – The contribution of fluvial sedimentary material discharged in the northwest of the Black Sea – Anthropic constructions, necessary for the development of ports (longitudinal and transversal protection hydrotechnical constructions). – Sea level variation. The Black Sea’s climate is influenced by the geographical position of the sea, the circulation of air masses, the wind regime, and other factors. The wind in the Black Sea area has the following characteristics: in the cold season, due to the influence of sea depression and ridge of the Siberian anticyclone, winds from the northern sector (northwest, north and northeast) are very strong along the coast, but are weaker at sea. In the warm season, the northwest, west, and southwest winds are predominant in the western part of the Black Sea and from the sea to the land in the other sectors of the sea, due to the predominance of the Azores maximum. The distribution of wind speed on steps for the Black Sea is as follows: 40–50% speeds between 1 and 5 m/s, 35–40% speed between 9 and 10 m/s, and 12–25% speeds between 11 and 15 m/s in the cold season (the frequency of winds with speeds higher than 15 m/s does not exceed 3–5%, up to 10% in the cold season). The types of wind circulation for the Black Sea area according to the wind directions (determined based on the distribution of the baric field on the sea and its surroundings) are the following: northeast, east, southeast, southwest, west, northwest, north, and weak circulation. The most probable average duration for these types of circulation is 6–24 h with a frequency of 67% (for cyclonic circulation the interval of 6–12 h represents 77% of the total cases). Regarding the air temperature regime, it can be concluded that the average annual temperature on the Black Sea coast is 10.0–15.2 C, with very hot summers and weak rainfall and warm and humid winters, except for the southeastern part of the Black Sea, where climate close to the subtropical. The lowest air temperatures at sea are during January and February, and the highest in July and August. The increase of the average annual temperature has a northwest-southeast orientation from 10 to 15.5 C, with a higher thermal gradient in winter and relatively low in summer. Atmospheric humidity follows the variation of air temperature. The water vapor tension varies from 16 mb in the SE to 14 mb in the NW. The thermohygrometric regime determines the atmospheric instability and the convective-turbulent variations with effect on the formation of clouds and cloudy systems, as well as the decrease of visibility and a wide range of meteorological phenomena. The hygrometric regime of the Black Sea is determined by the evaporation of the sea and the advection of Mediterranean and oceanic air; the annual value of the atmospheric circulation over the sea basin is estimated at 3,600 km3 of water. For the Black Sea basin, the average relative humidity has an inverse variation to the temperature variation. The spatial distribution of water vapor tension always has

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the gradient oriented in the direction of the sea. The relative moisture isolines are approximately parallel to the shore, with higher values towards the center of the sea. The average annual nebulosity in the Black Sea area is about 5.6 tenths. In the cold season, the nebulosity has a more homogeneous distribution than in the warm and transition season. The physical-geographical conditions of relative isolation, typical of the Black Sea, require that the exchange of water to and from the Black Sea be insignificant in relation to the total volume of water in its basin. The water level of the Black Sea is subject to periodic and non-periodic vertical oscillations. Volume oscillations are due to changes in the balance of the hydrological balance (seasonal oscillations, maximum in the cold period and minimum in the cold year). The secular variation of the Black Sea level has an oscillating character, with a tendency to increase in the last 100 years as a result of the increase of the volume of discharged water and of the slow subsidence movements of the land. The level of the Black Sea generally followed the oscillations of the level of the Planetary Ocean. According to the latest marine geological research, it is considered that the RissWürm interglacial phase (when the sea level was higher than the current one) was followed by the following phases: lowering the level to about 100 m (lower Würm), raising the level to 0 m, decreasing the level to 80 m (upper Würm), and then increasing to the current level. As a result of sea level fluctuations, the Black Sea drainage basin has changed several times (e.g., the Danube flows into the Lower Quarter into Lake Dacian located at the western boundary of the Danube Delta marine plain). The decrease in sea level during glaciations is accompanied by a strong discharge of water in the direction of the remaining Black Sea lake (Dacian Lake clogging was more likely at the end of the post-Karangatan regression), the center of sedimentary deposits being the deep delta complex. The strictly deltaic environment rose after this phase and migrated to land, simultaneously with the rise of the beach (at the Surojnian level). The last Würmian glaciation and the drop in sea level ( 100 m) once again move the direction of the depocenter towards the edge of the shelf in the area of the deep deltaic complex. The changes of the geomedium determined changes of the coastal area and the position of the watercourses, the sedimentary contribution, as well as the salinity of the water from the fresh to the marine one (as a result of the increase in sea level and the connection with the Mediterranean Sea). The current variation in the Black Sea level is determined by several factors with a very different regime. Over time, the most important were the river input and the unevenness caused by the wind. Other factors that influence the variation of the sea level are the meteo factors (precipitations and evaporation, the unevenness produced by the wind, the variation of the atmospheric pressure) and, to a small extent, factors of cosmic nature (the tidal phenomenon). The general fund for seasonal and annual variation of the Black Sea level is due to the river contribution.

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Although the level increases become significant only in secular periods, level variations during storms play an important role in changing the basis of wave action; as a result of these increases, it changes in the direction of the approach of the shore and the extension of the strip from the emerged beach on which the final surge takes place. Important thermal variations occur only in the superficial layers of the Black Sea, up to the limit of the influence of waves and sea currents, while in most of the water volume, there is an obvious thermal inertia. In coastal areas, the convective mixture is made to a depth of 60–80 m. The distribution of the water temperature average at the sea surface generally follows the distribution of the air temperature annual average above the Black Sea basin. The annual average of the distribution of water temperature varies between 11 in the northern part of the sea (Odesa Gulf) and 16 in the eastern part (Batumi), with extreme values in the hot period (24 ) and in the cold period (1 ). The Black Sea, which is characterized by a brackish regime, has salinities located at values lower than 24‰ on the entire body of water, with very low values in front of the mouths of rivers in the northwestern sector. The surface water mass has an average salinity of 18 ‰, and the deep one over 24‰. In summer, the salinity is 15–17‰ (from 6‰ to 7‰ in the river area in the northwestern part of the Black Sea basin to the value of 19 ‰ and even 23‰ in the high seas), and in winter, it is lower by 0.5–0.6‰ compared to the value in the warm season due to the lower intake of fresh water at this time of year. The level of the Black Sea is increasing relatively by 0.1–12.2 mm/year. Water level fluctuations depend on the direction and speed of the winds, the contour and nature of the shores, and the topography of the seabed. The Seich periods in the Black Sea range from a few minutes to 13 h, and amplitude from a few centimeters to 2 m (exceptionally). In the Black Sea, the tide has insignificant values for navigation, of maximum 10 cm. Wind waves are higher in winter and autumn, when winds from the sea predominate; in the western basin of the Black Sea, the height of these waves is 6–8 m, with a maximum of 14 m; at the shore, their value varies from 4.3 m (Odesa) to 5.1 m (Tendra), 5.7 m (Sevastopol), 6 m (Constanţa), and 8 m on the mountain coast. Strong waves appear in winter (frequency 10% in some areas), and in summer, they are less frequent (3%). In the cold period of the year the frequency of the 6 sea state and higher is over 10% and of the calm and of the sea of degree one 20–30%. The predominant direction of wave propagation is north and northeast. The height of the waves during winter storms can reach 5–8 m. In the transition season the regime of the waves is kept the same as in winter with a direction of propagation but unstable and with heights sometimes of 6–7 m. During summer, the frequency of the 6 sea state and more is up to 2%, strong waves are formed from west to north with maximum heights of 6–7 m, but predominant are the waves of about 1 m. When moving to the cold season, the agitation of the sea remains similar to that of summer, and starting in October and November, the

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degree of agitation of the sea increases, the sea state 4 and more expands to 5–10% in some districts; the predominant direction of wave propagation is from the northeast and east and sometimes even from the south, with maximum heights of 6–7 m. In general, the length of the waves in the Black Sea is 30–50 m, with a period of 6 s, but in the eastern and southeastern districts, long wind waves of about 100 m are frequently formed, with a period of 10–12 s, and blasphemy waves with a length of 150–200 m, with a period of 15–17 s. Waves in the Black Sea influence the safety of ships, both in the coastal area and at sea. This influence is manifested by the following effects produced on a ship: the ship’s drift; accentuating the oscillations of the ship, especially the roll; reduction (loss) of stability; loss of speed. In the Black Sea the sea current regime is present as one specific to as isolated basin, with specific features in some areas. This is determined by the wind regime, the river water input, the variation of water density, and the relief of the seabed. The main current comprises the whole sea in the form of a circle with a diameter of 20– 50 nautical miles located at a distance of about 2–5 nautical miles from the shore, to depths of 1000 m. In this area, it is characterized by stability and speeds between 0.5 and 1.09 Kt (2–3 Kt during the action of strong winds). The movement is performed counterclockwise, parallel to the shore, and very rarely has a reverse direction. In the central areas of the eastern and western basins of the Black Sea, there are circular currents with a counterclockwise movement and a weak and moderate speed of 0.2– 0.5 Kt. In gulfs and bays there are circular currents moving clockwise with speeds of 0.2–0.5 Kt. There are four important branches of this cyclonic movement: the Anatolian current, the Caucasus current, the Crimean current, and the Rumel current (receives a movement impulse from the rivers of the northwestern part of the Black Sea, along the west coast, carrying water masses from east to west and then south). The wind currents depend on the wind and wave regime, so that, after strong storms, their measured speeds are as follows: over 2.4 m/s in the Odesa area; over 1.9 m/s in the Eupatoria area; 2.2 m/s in the Yalta, Tuapse, and Batumi area; and 1.8 m/s in the Constanţa and Varna area. The Black Sea is open to navigation all year round. The periods of time with fog and ice do not exceed 18 days, respectively, 80–110 days/year in the north-western part of the Black Sea, near the shore in very cold winters. The storms, although not very frequent, in the last decades, were generally short lived, but with a special intensity, which caused great problems, loss of life, over 500 people, and ships, over 60, great material and financial damage. The Black Sea has its own biological characteristics, being considered “unicum hidrobiologicum,” peculiarities that are due to the genesis and paleogeographic past of the Pontic Basin, its geographical position, and the hydrological characteristics of tributary rivers. The evolution of the Black Sea fauna is related to the paleogeographic evolution of the sea basin. From the old Sarmatic Sea (with brackish waters), the Black Sea evolved with intermittent connections with the Mediterranean Sea, which caused the fauna to change, sometimes dramatically, from a tropical marine form to a brackish one and then to a marine one. Thus, currently in the Black Sea, there are exponents of several types of fauna, classified into four distinct groups:

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Ponto-Caspian elements (Caspian relics), North Atlantic and Arctic elements, Mediterranean elements (80%), and typical freshwater elements due to river input. Important research have revealed 3774 species of multicellular organisms, from which 1619 are algae, fungi, and superior plants; 1983 are invertebrate species; 168 are fish species; and 4 mammal species, also numerous varieties of microorganisms (viruses, bacteria, microalgae, fungi, protozoa). Due to the existence of hydrogen sulfide (90% by volume), from a depth of over 200 m and even less, there are only sulfur-reducing bacteria. Also, in the analysis of the hydrobiology of the Black Sea, it must be taken into account that although the sea level is 0.5 m higher than that of the Marmara Sea (due to the difference in density), the water exchange is noticeable only up to depths of 100–200 m, and for the northwestern part of the sea, the massive inflow of river waters also intervenes. The complex analysis of the physical-geographical, demographic, and economic potential of the countries of the Black Sea basin, with direct implications in maritime transportation, shows the following: the territory of the coastal countries represents 13.17% of the Earth’s surface; the population of coastal countries (2019) represents 5.15% of the world’s population. In recent years, there have been positive changes in the economic development of the countries bordering the Black Sea, reflected in the current value of the main economic indicators, as follows (Word Data Atlas – 2021): Human Development Index, 2019 (1 = the most developed): No. 1. 2. 3. 4. 5. 6. 7.

Rank 49 52 54 56 61 75 89

Country Romania Russian Federation Turkey Bulgaria Georgia Ukraine Republic of Moldova

HDI 0.83 0.82 0.82 0.82 0.81 0.78 0.75

Gross domestic product in current prices, 2020 in billion US dollars, 3.5% from world total: No. Rank Country Billion US dollars 1. 11 Russian Federation 1464.08 2. 18 Turkey 949.44 3. 45 Romania 248.62 4. 57 Ukraine 142.25 5. 70 Bulgaria 67.92 6. 117 Georgia 16.32 7. 136 Republic of Moldova 11.24

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GDP per capita, 2020, in US dollars: No. Rank Country 1. 58 Romania 2. 65 Russian Federation 3. 66 Bulgaria 4. 77 Turkey 5. 100 Georgia 6. 103 Republic of Moldova 7. 121 Ukraine

Abstract

US dollars 12,813 9972 9826 7715 4405 4268 3425

Total primary energy production, 2018, in quadrillion Btu: No. Rank Country Quadrillion Btu 1. 3 Russian Federation 63.45 2. 41 Turkey 1.76 3. 38 Ukraine 2.37 4. 52 Romania 1.07 5. 70 Bulgaria 0.47 6. 108 Georgia 0.09 7. 136 Republic of Moldova Total 69.21 Exports of goods and services in current prices, 2019, in thousand US dollars: No. Rank Country Thousand US dollars 1. 17 Russian Federation 482,635,570 2. 28 Turkey 246,992,000 3. 39 Romania 100,900,150 4. 50 Ukraine 63,566,000 5. 59 Bulgaria 43,167,570 6. 89 Georgia 9,544,767 7. 108 Republic of Moldova 3,650,850 Total 950,456,907 Imports of goods and services in current prices, 2019, in thousand US dollars: No. Rank Country Thousand US dollars 1. 19 Russian Federation 353,598,630 2. 27 Turkey 226,521,000 3. 35 Romania 110,531,571 4. 46 Ukraine 76,067,000 5. 58 Bulgaria 40,849,240 6. 92 Georgia 11,105,361 7. 106 Republic of Moldova 6,610,794 Total 714,752,025

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Total electricity net generation, 2019, in billion kilowatt-hours: No. Rank Country Billion kilowatt-hours 1. 4 Russian Federation 665.47 2. 15 Turkey 160.24 3. 28 Ukraine 54.27 4. 40 Romania 22.61 5. 43 Bulgaria 18.54 6. 64 Georgia 2.68 7. 57 Republic of Moldova 5 Total 928.81 Production of crude oil including lease condensate, November 2020, in thousand barrels per day: No. Rank Country Thousand barrels per day 1. 2 Russian Federation 9,351.42 2. 24 Turkey 63.04 3. 22 Romania 95.04 4. Ukraine 33.5 Total 9,543 Total primary coal production, 2018, in thousand short tons: No. Rank Country Thousand short tons 1. 3 Russian Federation 476,919 2. 5 Turkey 99,205 3. Bulgaria 33,359 4. Ukraine 28,882 5. Romania 26,066 6. Georgia 153 Total 664,584 Cereals production quantity, 2018, in million tonnes: No. Rank Country Million tonnes 1. 5 Russian Federation 109 2. 8 Ukraine 69 3. 17 Turkey 34.3 4. 19 Romania 31.5 5. 40 Bulgaria 9.9 6. 57 Republic of Moldova 3.4 7. 124 Georgia 0.371 Total 257.471

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Vegetables primary production quantity, 2018, in tonnes: No. Rank Country Tonnes 1. 4 Turkey 24,137,627 2. 10 Russian Federation 13,717,071 3. 16 Ukraine 9,517,223 4 35 Romania 3,230,406 5. 98 Bulgaria 499,206 6. 113 Republic of Moldova 279,184 7. 129 Georgia 142,100 Total 51,522,817 Bovine meat domestic supply, 2018, in thousand tonnes: No. Rank Country Thousand tonnes 1. 5 Russian Federation 1947 2. 37 Ukraine 314 3. 14 Turkey 1089 4 74 Romania 109 5. 118 Georgia 27 6. 119 Bulgaria 25 7. 144 Republic of Moldova 7 Total 3518 Number of arrivals, 2018, in million tourists: No. Rank Country 1. 6 Turkey 2. 16 Russian Federation 3. 31 Ukraine 4. 35 Romania 5. 42 Bulgaria 6. 59 Georgia 7. 139 Republic of Moldova Total

Million 45.7 24.5 14.1 11.7 9.2 4.7 0.160 110.060

Military expenditure in constant prices of 2011, 2014, in million USD dollars: No. Rank Country Million US dollars 1. 16 Turkey 20,448 2. 4 Russian Federation 65,103 3. 35 Ukraine 5229 4. 38 Romania 4945 5. 56 Bulgaria 2127 6. 102 Georgia 316 7. 136 Republic of Moldova 44 Total 98,212

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The analysis of the evolution of the Black Sea coastal states’ merchant fleets shows a decrease in the number of merchant ships (less in Turkey and Russian Federation), which demonstrates the crisis in maritime transportation in these countries): the merchant fleet of the Black Sea’s coastal states has a total displacement of about 53 million dwt (the world’s merchant fleet in 2020 has a displacement of 2 billion dwt). Total number of merchant vessels is over 4,800 (over 4% of world total of over 98,140 vessels). The total number of the Black Sea’s important ports is 57, of which 18 are considered main ports: Romania—8, out of which 4 are inland, main port: Constanța; Bulgaria—5, main port Varna; Turkey—12, main port Istanbul; Georgia—5, main port Batumi; Russia—11, main port Novorossiysk; Ukraine—15, out of which 4 are inland, main port Odesa; Republic of Moldova: main port Giurgiuleşti (on the Danube River). Modern maritime transportation is a complex, profitable long-term activity that involves in-depth knowledge of the field, which includes complex knowledge in many areas: theory and technique of maritime transportation; maritime economy; ship’s mechanics and construction; maritime geography; meteorology and oceanography; electronics, electrical engineering, and automation; informatics; marketing; ergonomics; and sociology, all in a unitary whole called maritime transport management, subordinated to very strict criteria: quality, efficiency, and safety. The volume of cargo traffic in the Black Sea’s ports (in million metric tonnes) has increased from 415 in 2015 to approx. 480 million metric tons in 2019. The containerized seaborne trade is a modern integrated system of human economic activity based on the principles of economic efficiency. In the Black Sea, the total volume of containerized seaborne trade exceeded 3 million TEU in 2018. Also, the countries bordering the Black Sea are currently developing programs for the construction of modern container terminals. The safety of navigation and the hydrometeorology warning systems in the Black Sea is a complex and laborious activity, without which a safe and fast maritime transportation can no longer be conceived today. In the Black Sea, there are several hundred light and non-light aids to navigation, which are the responsibility of the specialized institutions of the coastal states. On the Black Sea routes, the modern electronic and satellite navigation systems, with a high degree of technical complexity, ensure a special precision in determining a ship’s position.

Introduction

This book is a complex, applied presentation of the Black Sea geography and oceanography. It analyzes the historical, geographical, socio-political, and economic influences on navigation and seaborne trade in the Black Sea basin. The Earth is a maritime world, with the water surface representing approximately 72% of its total surface. For most people, this reality must be many a time demonstrated. The statistical data support these truths: more than 600 million people (around 10% of the world’s population) live in coastal areas that are less than 10 m above sea level; nearly 2.4 billion people (about 40% of the world’s population) live within 100 km (60 miles) of the coast. Oceans and coastal and marine re-sources are vital for people living in coastal communities, who represent 37% of the global population in 2017 [1]; 80% of the capitals of the world are under 300 nautical miles distance from the shoreline, and over 50% of the strategically located objectives (namely, towns with over 100,000 inhabitants, mineral oil fields, important economic areas) are situated at smaller distances than 100 nautical miles from the sea coast, with the sea representing the reserve of raw material and food for humanity and the seaborne trade representing over 90% of the total world trade [1]. Under these circumstances, quick, unprecedented development of maritime economic activities can be expected, and the competition for maritime space supervision will be more intense. The great actors of geopolitics are enlarging the development area of the global ocean and are submitting new doctrines regarding the land upon sea supervision. Therefore, although the geographical factor seems to have lost its importance in the world power equation, such a thing is contradicted by reality. The sea has always been used to link different points of a continent, either for troop and armament or goods and passenger transportation. Communications achieved in this manner and known today as maritime communications include, in modern acceptance, the recognized navigation routes, known and exploited in the whole world, the seaports, and the means of transport as well as the economic and political relations, which ensure this complex worldwide socio-economic process is carried out under safe conditions. From the geographical–economic point of view, maritime communications can be defined as economic infrastructure elements (namely, its prolongation into the xvii

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sea) of countries with access to the sea as well as of others, i.e., the landlocked countries that are promoting most of their commercial interests on the sea, too. The commercial maritime routes’ organization and development have been determined by the political and economic evolution of the coastal states, but they are directly influenced by the geographical and military factors as well. The free access to the sea, its custody or loss, maritime spaces’ supervision, naval exercises in maritime strategically points of direct or indirect influence are always in connection with the increase or decrease of a state’s political and economic power. The power of the Mediterranean or Western-European states has been affirmed in close connection with access and supervision of the resources, as well as with sea trade. The growing number of navigators that had a dual purpose, i.e., political and economic has had as a result, the sea is more and more traveled and known by the human race. Nowadays, maritime trade is a large and complex economic activity taking into account the transported goods’ value, as well as their material value, where enormous investments in high technology, represented by ships and ports, can be added. In 2018, global seaborne trade volume reached 11 billion tons, and shipments expanded by 2.7%, a rate estimated at 2.6% in 2019 [2]. In 2019, maritime trade volumes expanded by 0.5%, down from 2.8% in 2018, and reached a total of 11.08 billion tons [3]; in tandem, global container port traffic decelerated to 2% growth, down from 5.1% in 2018 [3]. At the beginning of 2020, according to the statistics of the World Maritime Organization, the world’s commercial fleet consisted of 98,140 vessels and reached a displacement of 2,061,944 thousand dwt (2.61% growth), out of which the modern multifunctional vessels and the container ships have an essential role. The highest increase was recorded for gas carriers (+6%), oil tankers (+5.8%), bulk carriers (+3.9%), container ships (+3.3%), and chemical tankers (+2.9%) [3]. In ancient times, the Black Sea was at the edge of the known world; along its coasts, it has preserved traces of the Greek, Roman, and Byzantine civilizations, many of the ancient ports being essential towns then, a role they have maintained to the present. The complex geographical conditions that have influenced and that influence further the development of the maritime trade and transport in the Black Sea are not thoroughly known and used for the optimization of these activities. Also, together with the economic development of coastal states, the increase of maritime traffic, and ports’ growth (there are already many projects for the modernization of some important ports), numerical and qualitative increase of commercial fleets in the Black Sea are expected. The role of the geographical position of Romania, a country with access to the Black Sea as well as other coastal states, for its socio-political and economic development, respectively, is not yet thoroughly understood and appreciated. Therefore, I consider a profound study of some lines of research is of real and present interest, such as determination of the multiple implications of Romania’s geographical settlement near the Black Sea on its national and economic development; determination of the geographical factor’s influence on maritime transport and

Introduction

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naval industry development; determination of the initiation and application needs of some economic development programs as well as the protection of the Romanian coastal and marine areas; and determination of the requirements concerning the insurance of Romanian maritime communications in the Black Sea (area) following the new international juridical frame. The Black Sea represents a physical-geographical, political-social, cultural, and economic entity that today extends far beyond its recognized geographical area, usually known under this name. Lately, the geostrategic importance of the Black Sea basin is emphasized by the perseverance with which the main “actors” of the world’s politics and economy have expressed their interest and the will in various political, diplomatic, economic, cultural, military, and scientific research actions mainly carried out in this area in the last few years. Since 1991, six coastal states have had direct access to the Black Sea: Romania, Bulgaria, Turkey, Georgia, Russian Federation, Ukraine, and, indirectly through the Danube River, Republic of Moldova (which can be considered a Black Sea riparian country). For four of them (Ukraine, Romania, Bulgaria, and Georgia), the Black Sea represents their sole maritime access point. Because of its specific geographical characteristics, including its depth, the Black Sea has a vast “hinterland” composed of countries with maritime access due to the Danube River [4]. The Black Sea started to play an essential role in the geopolitical considerations only when the threat coming from that direction started to become greater and greater. Today, the importance of the Black Sea is given by its geostrategic position, surface—over 420,000 km2, coastline length—over 4800 km, population—over 160 million, 18 major ports, and 10 large rivers flowing to the sea—total river input exceeding 350 km3/year, rich in energy sources (currents, offshore wind, H2S, gas hydrates) [5]. The Black Sea’s position, namely a bridge between the East and the West, at the crossroads of civilizations, as well as the importance of the neighboring states, close to the Black Sea coastal states, or those that have political and economic interests here, have aroused the attention of researchers from different fields of activity. In this sense, multidisciplinary research activities were planned for several years, with the attendance of representatives from some countries and institutions located at significant distances from the Black Sea, who have had little interest in this area in the recent past. It is necessary for the coastal states of the Black Sea to intensify their presence in all activities, to strengthen their unique geostrategic positions, at the political as well as economic, military, cultural, scientific, and sports levels. The Black Sea from Paleogeography to Modern Navigation continues the author’s research, undertaken throughout the doctoral thesis and defended at the University of Bucharest. This book is addressed to all those who love the fascinating history and the dynamic present of the Black Sea.

Contents

1

2

3

The Black Sea Basin, Physical–Geographical Conditions . . . . . . . 1.1 The Main Steps in the Paleogeographical Evolution of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1.1 The Submarine Coast and Relief, as a Reflection of the Paleogeographical Evolution of the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 The Specific Elements in the Paleogeographical Evolution of the Romanian Black Sea Coast . . . . . . . . . . . . . . . . . . . . . 1.3 Coast Evolution in Holocene . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.

1

.

4

.

6

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8 10 14 26 27

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31 32 33 43

. . .

43 43 49

. . .

51 60 61

The Morphohydrography and Morphodynamics of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 The Hydrographic Network of the Black Sea Basin . . . . . . . . . . 3.2 The Black Sea Morphodynamics . . . . . . . . . . . . . . . . . . . . . . .

63 63 74

The History of Research Conducted in the Black Sea . . . . . . . . . . 2.1 Black Sea Research in the Nineteenth Century . . . . . . . . . . . . 2.2 Black Sea Research in the Twentieth Century . . . . . . . . . . . . . 2.3 Black Sea Research in the Twenty-First Century . . . . . . . . . . . 2.3.1 Marine Research Institutions in the Black Sea Coastal States . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2 Marine Research Vessels in the Black Sea . . . . . . . . . 2.3.3 International Organizations in the Black Sea Region . . 2.3.4 International Programs/Projects in the Black Sea Region in the Twenty-First Century . . . . . . . . . . . . . . 2.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxi

xxii

Contents

3.2.1

The Coast Aspect in the Western Basin of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.2 The Sea Bottom’s Relief and the Depths of the Western Basin of the Black Sea . . . . . . . . . . . . 3.2.3 The Sea Bottom’s Nature in the Western Basin of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . 3.2.4 The Coast Aspect in the Eastern Basin of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.5 The Sea Bottom’s Relief and the Depths of the Eastern Basin of the Black Sea . . . . . . . . . . . . 3.2.6 The Sea Bottom’s Nature in the Eastern Basin of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . 3.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

5

The Influence of the Coastal Relief on the Navigation and Seaborne Trade in the Black Sea . . . . . . . . . . . . . . . . . . . . . . 4.1 The Black Sea Coast’s Lights . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Black Sea Basin’s Meteo-Climatic Characterization . . . . . . . . 5.1 Anemobaric Regime, Atmospheric Circulation, and Wind Regime in the Black Sea Basin . . . . . . . . . . . . . . . . 5.1.1 Atmospheric Pressure Conditions in the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.2 The Atmospheric Circulation in the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.3 The Winds’ Regime in the Black Sea Basin . . . . . . . . 5.2 The Air Masses and the Atmospheric Fronts in the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.1 The Air Masses and the Atmospheric Fronts in the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . 5.2.2 The Storms Regime in the Black Sea Basin . . . . . . . . 5.3 The Thermohygrometric Regime. Effects on Temperature Variation and Humidity. Weather Phenomena . . . . . . . . . . . . . 5.3.1 The Air Temperatures in the Black Sea Basin . . . . . . . 5.3.2 The Atmospheric Humidity Regime in the Black Sea Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3 The Nebulosity Regime in the Black Sea Basin . . . . . 5.3.4 The Precipitation Regime in the Black Sea Basin . . . . 5.3.5 Specific Meteoclimatic Elements Along the Romanian Black Sea Coast . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Black Sea’s Main Ports Meteorological Data Analysis . . . . . . . 5.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.

76

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84

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85

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86

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88

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89 90 92

. 95 . 97 . 112 . 114 . 115 . 115 . 115 . 119 . 122 . 126 . 127 . 132 . 138 . 139 . 145 . 148 . 148 . . . .

151 163 171 172

Contents

6

7

8

9

The Influence of Weather and Climate Factors on the Navigation and Seaborne Trade on the Black Sea . . . . . . . . . . . . . . . . . . . . . . 6.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Short History of the Black Sea’s Storms . . . . . . . . . . . . . . . . . 6.2.1 The Storm on February 5–6, 2020 . . . . . . . . . . . . . . . 6.3 Naval Accidents in the Black Sea . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Specific Hydrological Factors of the Black Sea Basin . . . . . . . 7.1 The Water Balance and the Water Exchange Through the Straits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 The Black Sea Thermohaline and Density Regimes . . . . . . . . . 7.2.1 The Ice Regime in the Black Sea . . . . . . . . . . . . . . . . 7.2.2 The Thermohaline and Density Regime of the Black Sea Waters . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.3 The Hydrodynamics of the Black Sea Waters: Level Oscillations, the Waves, and Marine Currents in the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Influence of the Hydrological Factors on Navigation and Seaborne Trade on the Black Sea . . . . . . . . . . . . . . . . . . . . . . 8.1 The Influence of the Marine Currents on Navigation and Maritime Transportation on the Black Sea . . . . . . . . . . . . 8.2 The Influence of the Hydrological Factors on the Black Sea Coast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 The Influence of the Waves on the Activities in the Black Sea Ports and Harbors . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 The Waves’ Influence on Maritime Navigation in the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5 The Influence of Hydrological Factors on the Vessel’s Rolling Motion and Pitching in the Black Sea . . . . . . . . . . . . . 8.6 The Influence of Hydrological Factors on a Ship’s Stability in the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 The Speed Loss on the Waves Under the Black Sea Navigation Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrobiological Elements Specific to the Black Sea: Black Sea Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Hydrobiological Elements Specific to the Black Sea . . . . . . . . 9.2 Black Sea Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.1 Threats and Pressures in the Black Sea’s Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxiii

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175 184 186 191 202 209

. 211 . 211 . 217 . 227 . 229

. 242 . 266 . 268 . 271 . 271 . 272 . 275 . 276 . 279 . 285 . 290 . 290 . 292 . 295 . 295 . 303 . 303

xxiv

Contents

9.2.2 Black Sea’s Pollution . . . . . . . . . . . . . . . . . . . . . . . . 9.2.3 Invasive Species in the Black Sea . . . . . . . . . . . . . . . 9.3 The Romanian Black Sea Coast: Hydrobiological Elements . . . 9.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

The Historical, Social, Political, Economic, and Geopolitical Framework of the Black Sea Basin Influencing Maritime Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1 The Historical, Social, and Political Framework of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 The Black Sea Coastal States . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.1 Romania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.2 Bulgaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.3 Turkey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.4 Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.5 The Russian Federation . . . . . . . . . . . . . . . . . . . . . . 10.2.6 Ukraine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.7 The Republic of Moldova . . . . . . . . . . . . . . . . . . . . . 10.3 The Economic and Geopolitical Framework of the Black Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.1 World Economy Framework . . . . . . . . . . . . . . . . . . . 10.3.2 The Economic Power of the Black Sea Coastal States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.3 The Human Development Index (HDI-2018) of the Black Sea Coastal States . . . . . . . . . . . . . . . . . 10.3.4 Transport Links Between the Black Sea Region and Europe and Asia . . . . . . . . . . . . . . . . . . . . . . . . 10.4 Seaborne Trade in the Black Sea . . . . . . . . . . . . . . . . . . . . . . 10.4.1 The Black Sea’s Coastal States Merchant Fleet . . . . . . 10.4.2 The Black Sea’s Ports . . . . . . . . . . . . . . . . . . . . . . . . 10.4.3 Black Sea Romanian Ports . . . . . . . . . . . . . . . . . . . . 10.4.4 Black Sea Bulgarian Ports . . . . . . . . . . . . . . . . . . . . . 10.4.5 Black Sea Turkish Ports . . . . . . . . . . . . . . . . . . . . . . 10.4.6 Black Sea Georgian Ports . . . . . . . . . . . . . . . . . . . . . 10.4.7 Black Sea Russian Ports . . . . . . . . . . . . . . . . . . . . . . 10.4.8 Black Sea Ukrainian Ports . . . . . . . . . . . . . . . . . . . . 10.4.9 Ports of Republic of Moldova . . . . . . . . . . . . . . . . . . 10.5 The Black Sea Ports Cargo Throughput . . . . . . . . . . . . . . . . . 10.5.1 The Port Traffic Capacity in the Black Sea . . . . . . . . . 10.5.2 Seaborne Trade in the Black Sea . . . . . . . . . . . . . . . . 10.6 Main Sea Routes in the Black Sea . . . . . . . . . . . . . . . . . . . . . 10.6.1 Black Sea Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.2 Black Sea Ferryboats Lines . . . . . . . . . . . . . . . . . . . . 10.6.3 Safety of Navigation in the Black Sea . . . . . . . . . . . .

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304 310 311 313 315

. 319 . . . . . . . . .

319 357 358 359 360 362 363 364 366

. 367 . 367 . 367 . 371 . . . . . . . . . . . . . . . . . .

380 383 386 388 391 410 414 418 421 426 434 434 434 435 447 447 451 451

Contents

10.7

The Geopolitical Importance of the Black Sea . . . . . . . . . . . . . . 10.7.1 The importance of the Black Sea in the Twenty-First Century. Black Sea “The Majestic Swan of Europe” . . . 10.7.2 The Extended Region of the Black Sea . . . . . . . . . . . . 10.7.3 The Geographic Potential of the Black Sea Coastal States 10.7.4 The Military Dimensions of the Black Sea Basin . . . . . 10.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxv

453 456 457 457 458 458 466

POSTFAŢĂ (In Romanian) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475 Afterword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477

Chapter 1

The Black Sea Basin, Physical– Geographical Conditions

Abstract The Black Sea is a natural inland water basin situated between Europe and Asia and has the aspect of a deep basin, oriented from west to east, stretching on approximately six degrees of latitude and five degrees of longitude, an intercontinental sea, being connected to the Mediterranean Sea through the Bosporus Strait and to the Azov Sea through the Kerch Strait. The actual shape of the Black Sea probably appeared about 40 million years ago, at the end of the Paleolithic period (Miocene, Mio-Pliocene), respectively, when the structural raises from Asia Minor detached the Caspian basin from the Mediterranean basin; the Black Sea gradually separated from the Caspian region about 25 million years ago. The subsequent geological evolution produced changes to the sea level and, associated with the action of the Ice Age glaciers, formed intermittent connections with the Mediterranean basin (this phenomenon was happened about 6–8 million years ago). Keywords Black Sea · Geographical conditions The Black Sea is a natural inland water basin situated between Europe and Asia and has the aspect of a deep basin, oriented from west to east, stretching on approximately six degrees of latitude and five degrees of longitude, between the parallels: Lat. 40
550 N, Lat. 46
370 N and the meridian lines: Long. 27
270 E, Long. 41
470 E. It is an intercontinental sea, being connected to the Mediterranean Sea through the Bosporus Strait and to the Azov Sea through the Kerch Strait. The main physical–geographical data of the Black Sea (Table 1.1, Figs. 1.1 and 1.2) give it an individual character into the Euro-Asian context, in other words, a specific area [6]. The values obtained of the Black Sea area also vary in a large range: between 413,500 km2 and 436,000 km2. Other scientist: Zaitsev – 2008 [8] shows the following values of some dimensions of the Black Sea: area 423,000 km2, volume 547,000 km3, maximum depth 2212 m, and The Expert Group of the Blue Growth Initiative for Research and Innovation in the Black Sea – area 421,638 km2 [5]. The coastline length and area of the Black Sea have been studied and measured by many scientists (Ross et al., 1974; Nankinov, 1996; Loghin, 2000; Panin, 1999, 2007, 2009). For all of them, the coastline length ranges between 4020 km and over © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_1

1

2

1 The Black Sea Basin, Physical–Geographical Conditions

Table 1.1 The Black Sea: The main physical-geographical data 1. 2. 3. 4.

5. 6. 7. 8. 9. 10.

11.

Surface: 413,490 km2 (462,000 km2 together with the Azov Sea) Volume: 529,955 km3 Depth of permanent halocline: 50–200 m The maximum depth: 2212 m (the medium depth 1271 m)/2243 m Maximum length, on the parallel of 42
300 N, between Burgas and the Caucasian coast: 1149 km (662 nautical miles, nm) Maximum width (on the meridian of 31
120 E): 650 km (332 nm) Minimum width (on the Cape Sarych meridian–Crimea pen.): 267 km (144 nm) Coasts length: 4047 km (2200 nm) Distance up to the White Sea: approx. 1.300 km* Distance up to the Persian Gulf: approx. 1300 km* Extreme points: In the northern part 46
330 N at Berezan Estuary, near Ochakiv, in the eastern part 41
420 E between Batumi and Poti, in the southern part 40
560 N at Giresun, and the western part 27
270 E in the Burgas Bay Romanian coast: From Vama Veche to Musura mouth (256 km); the Ukrainian coast: from Musura mouth to Kerch Strait (1200 km); the Russian coast: from Kerch Strait to Psou River mouth (239 km); the Georgian coast: from Psou river mouth to Chorotka river mouth (310 km); the Turkish coast: from Chorotka river mouth to Rezovka river mouth (1695 km); the Bulgarian coast: from Rezovka river mouth to Vama Veche (378 km)

12. 13. 14. 15.

16. 17. 18. 19. 20. 21.

22.

Distance to the North Sea: approx.1300 km Distance to the Mediterranean Sea (Gibraltar): approx. 1300 km The surface of the hydrographical basin: 2,405,000 km2 The level difference between the Elbrus peak (5633 m) and the maximum depth: 7878 m Continental platform: 133,000 km2 (40% from the total sea surface) The flow of inlet water through the Bosporus Strait: 450 km3 The flow of freshwater: 400 km3 Distance up to the Suez Canal: approx. 650 km* Distance up to the Caspian Sea: approx. 350 km* Presence of the hydrogen sulfide: from the depth of 150–200 m

The shelf represents approx. 25% of the seafloor, (5–15 km on the largest part of the sea), is extended up to the depth of 100. . .200 m (140–160 m to the south of Sevastopol and Yalta), the depression is delimited by the isobath of 200 m. The area of the northwestern shelf is about 191,600 km2. The eastern and southern parts are very narrow—a few kilometers wide, and the western part—a few tens of kilometers. The continental slope (40%) lies to depths of 2000 m, with canyons and submarine valleys. The Black Seafloor (35%) is an accumulative flat plain decline toward the center [7]

* The distances to the geographical regions presented above are measured in a straight line

4400 km. A recent study (Stanchev et al., 2010) presents some new results for the area and coastline length of the Black Sea, based on the Landsat 7 satellite images and GIS technology. The estimated Black Sea coastline length is 4869 km, and its area is 421,638 km2 (Black Sea Strategic Research and Innovation Agenda, 2019). The results obtained could be considered comparable with the results from 1:50,000 scale topographical maps (Table 1.2) [10].

1 The Black Sea Basin, Physical–Geographical Conditions 28000’ E

3

36000’ E

32000’ E

40000’ E

Kherson Odesa Illichyvsk

Azov Sea Karkiniska Bay

Kerch Strait Kerch

Sulina

Kalamitska Bay Symferopol

Anapa

45000’ N Novorossiysk

Sevastopol Midia C ons tanţa 256 Mangalia

Varna

Yalta Tuapse

km

1200 km

239 km

332 M

Black Sea

378 km

Sochi

144 M

310 km

Sukhumi

43000’ N

662 M

Burgas

Poti

-2,212 m Cape Kerempe

1695 km

Batumi

Sinop

Zonguldak

Trabzon

Samsun Istanbul

41000’ N Izmit

Fig. 1.1 The Black Sea dimensions and its coastal states [9]. (Source: The author’s processing based on the map of Nicolaev and Bologa, GEO-ECO-Marina Review 11/2005)

1,300 km to the White Sea North Sea 1,300 km

Black Sea

350 km Caspian Sea

Gibraltar 1,300 km 650 km Suez

1,300 km to the Persian Gulf

Fig. 1.2 The Black Sea position in Eurasia. (Source: The author’s processing based on the Black Sea public map, http://www.emodnet.eu/black-sea)

Other authors [8, 11, 12] show that the Black Sea coastline is about 4,740 km (4838.1 km: Romania—245 km, Bulgaria—378 km, Georgia—312 km, Russian Federation—379 km, Turkey—1,695 km, Ukraine – 1,891.1 km) and 4125 km, respectively, in length, of which about 1450 km belong to Turkey and about 1330 km to Ukraine, and as for The Black Sea Basin, it has an area of 416,790 km2

4

1 The Black Sea Basin, Physical–Geographical Conditions

Table 1.2 The coastline length of the Black Sea No. 1 2 3 4 5 6 7

Country Romania Bulgaria Turkey Georgia Russian Federation Ukraine Total

Coastal length (km) 256 414 1700 322 421

Number of segments (m) 2129 5122 14,765 1387 2668

Average segments length (m) 120 81 116 322 421

1756 4869

13,787 39,858

128 122

and a water volume of 535,430 km3. Bulgarian scientists Dimitrov and Dimitrov (2004) show that the Black Sea lies between the parallels: Lat. 40
550 500 N, Lat. 46
320 500 N and the meridian lines: Long. 27
270 E, Long. 41
420 E, the total area is 423,000 km2, and together with the Sea of Azov—460,000 km2, the maximum depth of the basin is 2245 m and the average depth is 1271 m [13].

1.1

The Main Steps in the Paleogeographical Evolution of the Black Sea

There are many opinions regarding the genesis of the Black Sea cuvette. One of many points of view is that the Black Sea corresponds to a young geosyncline formed in Mio-Pliocene (Obruchev, 1926; Licikov et al., 1935; Arhanghelski and Strahov, 1938). Another hypothesis, a newer one, is regarding the secondary genesis of the Black Sea depression, following the transformation of the continental crust through deep metamorphism of the neoformation crust (Subotin, 1965). Slesinger (1978) considers that in the Miocene, the central depression and the continental slope were formed through a deep, but unequal, fall of the Black Sea depression. In the Superior Miocene and Pliocene, the Black Sea Basin was one with fresh and brackish water (the Pontic Great Lake); the surface developed (in the Neogene– Quaternary), and at the end of the Pliocene, it appears isolated and reduced in size. Starting with the Pleistocene, the Pontic basin broke up, and there appeared more basins that would clog; thus, only the actual basin of the Black Sea remained. From here on, the evolution and the characteristics of the Black Sea Basin have depended on the level oscillations of the World Ocean and of its oscillations, as well. In the Quaternary period, the oscillatory character of the sea level’s variation is exemplified by the Ceaudin and Paleoeuxin basins’ succession, with freshwater, higher levels, to the Pliocene basins, with lower levels [14]. The connection with the Mediterranean waters is made in Uzunlar when the sea level rises by 30–40 m over the actual one. Then, during the Riss Ice Age, new isolation of the Black Sea (a rather extended one) follows, when the sea level

1.1 The Main Steps in the Paleogeographical Evolution of the Black Sea

5

regression was around 200 m under the present one; after this, it recovered in Karangat, between the Riss and Würm Ice Ages, when the level rose to 5–20 m over the actual one. The connection with the Mediterranean Sea is again interrupted during the Würm Ice Age (around 20 thousand years ago) when the sea level fell to 80–100 m under the present level; this period is known as Neoeuxin, and it is characterized by fresh and brackish waters. Traces of the coastal valleys from that period can be observed today, especially on the continental platform [15]. What follows is the phase of the old Black Sea during the Post-glacial (Holocene) age, i.e., around 8–10 thousand years ago, when, as a result of the glaciers melting, the sea level rose by approx. 2 m over the present level and a permanent connection with the Mediterranean Sea was established. This is the moment when the process of the Danube Delta formation begins and according to some data (i.e., at approximately the limit between Pleistocene–Holocene periods) also the process of hydrogen sulfide formation [16]. During the period of the new Black Sea, i.e., about 4–5 thousand years ago, the sea level rose by five meters over the present level, when the Neolithic transgression (Histrian) took place. Up to the end of the second millennium BC till the beginning of the first millennium BC, the phanagorian regression followed, when the regression was of – 3–4 m compared to the present sea level and then the Vlach transgression from fifteenth century AD, when the sea level rose by around one meter over the actual level, then beginning to fall to the present level. According to Zaitsev (1977), the paleogeographical evolution of the Black Sea Basin has known the following stages (Fig. 1.3) [17]: 1. The Sarmatic Sea constitution (5–7 million years BC), like a basin of the Tethys Sea, which extended from the present position of Vienna city until the base of the Tian Shan Mountains and comprised approximately the present area of the Black Sea, the Azov Sea, the Caspian Sea, and the Aral Sea, separated by the World Ocean 2. The Meotic Sea formation (3. . .5 million years ago BC), having a connection to the World Ocean 3. The Pontic lake (sea) in the Pliocene period (1.5–3 million years BC), when the connection with the ocean is interrupted again and the saline water is replaced by freshwater almost entirely (the sea fauna is replaced by brackish and freshwater faunas, represented nowadays, inclusively, in the areas with low salinity from the Caspian Sea and the Azov Sea and in the north-western part of the Black Sea, respectively) 4. The Ceaudian Lake (sea), (1 million years BC), isolated by the ocean, with low salinity water (Kuma-Manych) and Pontic-type fauna 5. The Paleoeuxinian basin (400–500 thousand years BC), having almost the same shape as the present one of the Black Sea and the Azov Sea, connected in the north-eastern part with the Caspian Sea through the Kuma-Manych depression and in the south-western part with the Marmara Sea through the Bosporus Strait (this one not being connected with the Mediterranean Sea), and Pontic-type fauna

6

1 The Black Sea Basin, Physical–Geographical Conditions

The Sarmatic Sea

The Paleoeuxinian basin 5

1

The Meotic Sea

The Karangat Sea 6

2

The Pontic lake The Neoeuxin lake 7 3

The Ceaudian Lake

The modern Black Sea 8

4

Fig. 1.3 The paleogeographical evolution of the Black Sea Basin. (Modified after Zaitsev, 1978)

6. The Karangat Sea (100–150 thousand years BC), which had a connection to the Mediterranean Sea and the World Ocean; the salinity rose (higher than the present level) and the sea fauna and flora occupied a larger part of the sea basin. 7. The Neoeuxin lake (or sea) (18–20 thousand years BC); when the connection with the ocean is again interrupted; the salinity is reduced very much, the oceanic fauna and flora are disappearing, and the fauna and flora of Pontian type reoccupy the entire basin 8. The modern Black Sea (10–7 thousand years BC), when the connection with the Mediterranean Sea through Bosporus and Dardanelles straits is realized again; the salinity gradually rose, thus allowing the penetration of the area with numerous Mediterranean-type species (nowadays 80% of the Black Sea fauna comes from the Mediterranean Sea). The Pontic-type relics are again receding into lower salinity areas.

1.1.1

The Submarine Coast and Relief, as a Reflection of the Paleogeographical Evolution of the Black Sea Basin

The influence of the physical–geographical evolution of the Black Sea Basin on the coasts’ aspect and the submarine relief represents one of the focal points for the present work.

1.1 The Main Steps in the Paleogeographical Evolution of the Black Sea

HOLOCENE

PLEISTOCENE

Thousands of years

-1000

CEAUDA

-520

-490

PL2 PALEOEUXIN

WURM PL

EUXIN MED

-270

CARANGAT

GURIAN

WURM UZUNLAR

PL1

MINDEL POSTCEAUDA

GUNTZ

7

1

2

Postglaciation

*

Flandriana Neolitica Dobrogeana

*** **

Fanagoriana Histriana Dacica Techirghiol

3

3 NE

-57

* **

MNV MNV 8

0

2

*** Flandriana Neolitica Dobrogeana

0

Phases

Lacustrine

Fluvial-lacustrine Transgressions

Deltaic

River-marine

Litoral[marine

*** * Local names in Holocene

Inter glaciation Regressions

Fig. 1.4 Sea level variation in the Quaternary period. (Modified after Șelariu, 1999)

The sea level variation in the Quaternary period (according to Șelariu—the present Romanian research having particular importance for the coasts and submarine relief evolution is taken into account) is presented in Fig. 1.4. From these graphics results that the Black Sea Basin limits varied very little from the beginning of the Quaternary period, and the Danube river attained the area of its delta, in the same period [16]. Furthermore, all the quaternary marine deposits observed nowadays are coastal deposits because the differences between the quaternary coasts’ configuration and the present ones are insignificant [18]. The research conducted in the Black Sea in the eighth decade showed that the sea basin is divided into four main physiographical provinces, i.e., the continental platform, the continental slope, the Piedmont, and the abyssal plain [19]. The continental platform represents 29.9% of the total surface of the Black Sea Basin, the continental slope 27.3%, the Piedmont 30.6%, and the abyssal plain 12.2% [19]. The abyssal plain stretches over the central part of the sea and is characterized by an extremely flat and smooth relief, and the maximum measured depth is 2212 m, in an area situated 60 km north of Inebolu [19]. Although the margin of the shelf is found at variable depths, almost everywhere the slope breach towards the continental slope (at 100. . .110 m) is accompanied by the presence of a step of 10–12 m height, interpreted as being the limit of the sea basin in one of its quaternary stages [20]. Moreover, in the areas where the continental platform’s passing occurs at depths of 400–500 m, there are more steps (at about 100 m), probably representing quaternary fossil sea-walls [21].

8

1.2

1 The Black Sea Basin, Physical–Geographical Conditions

The Specific Elements in the Paleogeographical Evolution of the Romanian Black Sea Coast

A complex evolution characterizes the Romanian Black Sea coast, pointed out in the works of Romanian researchers Liteanu et al. (1961), Liteanu and Pricăjan (1966), Panin (1974), Şelariu et al. (1969), Trufaş (1970, Caraivan, Şelariu (1974), Mihăilescu and Rogojină (1984), Caraivan et al. (1986, 2013); Panin et al. (1977), Panin (1972, 1974, 1976, 1983, 1989, 1997, 1998, 1999), Rădulescu (1988), Mihăilescu (1989), Vespremeanu and Ştefănescu (1978, 1993) [22, 23] (Fig. 1.5). In Fig. 1.5, the variation of the sea level that occurred in the Middle and Superior Pliocene is represented by the curve, and the relative difference of this (with segments of straight lines) is represented by the straight line segments. Coast Evolution in the Pleistocene At the beginning of the Neoeuxin period, the sea level was 80 m lower than the present level, a regression followed by the continental valleys deepening and detrital material transport, the shelf having the aspect of a coastal plain. The drillings of the coastal cordons certify the fact that the würmian relief developed on different

Legend Dacian regression Black Sea New

Shore line - end of Neoeuxin phase

Blacks

ea’s Sh

elf

Black Sea Old

Fig. 1.5 Paleogeographical evolution of the Romanian Black Sea coast

1.2 The Specific Elements in the Paleogeographical Evolution of the Romanian. . .

9

substrata. In the second part of the Neoeuxin period, the evolution of the shelf of the sea continues in the direction of the basic level, i.e., towards – 40 m (compared to the present level), resulting in the evolution of the Dobrogean rivers’ valleys up to their balance profile, a rising which causes their clogging. The variation of the Black Sea level in the Pliocene period, demonstrated through the prospectings conducted on the coast and shelf regions of the northern part of the Black Sea (Chepaliga et al., 1982), indicate the fact that three transgressions occurred in the Middle Pliocene and later a fourth one in Ceauda (Pleistocene) [21] (Fig. 1.6). In support of this claim, the scheme of the erosion of the NE coast of the Black Sea Basin in the Pliocene period (Yesin 1993) [21] is represented below (Fig. 1.7). In Fig. 1.7, the three terraces constituted in the Pliocene period, in a period of 2.9 million years (at the end of the Ceauda transgression they had the level +(440. . .470) Black Sea level variation in the Middle and Superior Pliocene m Black Sea approximate level variation in the same period 0

-50

-100

3,5

3,0

2,5

2,0

Million of years

1,0

1,5

Fig. 1.6 The sea level variation in the Middle and Superior Pliocene. (Modified from Chepaliga et al., 1982)

Height [m] 700

5

6

7

8

9

10

11

600 500 400 300 200 100 0

Present level of the sea

Fig. 1.7 The erosion of the NE coast of the Black Sea, taking place in the Pliocene period. (Modified after Yesin, 1993)

10

1 The Black Sea Basin, Physical–Geographical Conditions

m, +330 m, and +130 m, respectively), are represented. During the following 600,000 years, the coast further rose to the level of the present Caucasian terraces [19].

1.3

Coast Evolution in Holocene

A characteristic of this period of the final opening of Bosporus is the Flandrian (Dobrogean) transgression and the sea level rising almost to the present level. In the beginning, an increase of the sea level, followed by the coastline retiring towards the west, up to approximately the present isobath of 15 m, is distinguished. During the new Black Sea period, the transgression continues, a level rising up to +4 m is recorded. As a result of these oscillations of the sea level, important modifications of the coastline and submarine relief were produced, especially in the northern part. The post-glacial transgressions had as a consequence the drowning of the valleys, the destruction and washing of the old coastline, and of some coastal cordons, whose positions in the sea are difficult to identify [16]. An essential regression follows, determined by a cold climate, when the sea level falls to 2, 3 m compared to the present level (a process that took place until the first centuries of the first millennium AD, a period from which submarine archeological traces are preserved to this day, such as the ruins of Histria, Callatis, and Tomis citadels, fishermen settlements on the „Grindul Lupilor” or around the former Techirghiol bay, etc.). The actual transgression is evidenced by the banks’ transferring to the land, the isobaths retreat to the coast, some cadastral landmarks remaining in the sea, etc. [16]. There is a supposition according to which the coastlines which obstructed the lagoons from the Danube’s mouths advanced in the high seas, forming a coastline much more to the east compared to the present one. In the case of different transgressive or regressive phases, the Dobrogean basis spurs had an essential role for the coastal cordons orientation, formed especially of green schists and Cretaceous sandstones, which extend under more recent deposits, e.g., the “Grindul Lupilor,” or appear as rocky islands or peninsula (Bisericuţa, Histria, etc.). These represented the nuclei of the formation and orientation of the coastal cordons at the entrance in the Halmyris bay (the present Razim) and the old bank from Istros (Danube) mouths, a fact mentioned by Herodotus (Fig. 1.8) [22, 23]. In N. Panin’s opinion (1997) [22], the paleogeological evolution of the Danube Delta had as main phases the initial phase Letea-Caraorman (11,700–9800 BC), the first Sfîntu Gheorghe Delta (9000–7200 BC), the Sulina Delta (7200–2000 BC), the second Sfîntu Gheorghe Delta and Chilia Delta (2800 BC–present), and the secondary Coşna-Sinoe Delta (3550–2500 BC) (Fig. 1.9). Recent research (Vespremeanu-Stroe et al., 2017) shows the delineation of the Danube Delta lobes (including bayhead, lacustrine, and open-coast lobes) at their maximum extension: SG1—Old Sfântu Gheorghe; S—Sulina; D1—Old Dunavăţ; D2—New Dunavăţ; SG2—Modern Sfântu Gheorghe; C1—Chilia 1; C2—Chilia 2; C3—Chilia 3, where the numbers express their chronological succession of the

1.3 Coast Evolution in Holocene

11

Lake Thiagola

Psilon Boreion Peudostoma

Istros

Peuce

Calon Naracum Hieron Stoma

Noviodunum Pteron Histria Tomis Callatis Dyonisopolis Tirisis Odessos

Fig. 1.8 The Dobrogean coast in the Old Ancient period, processing after Panin (2001) Chilia 2.000 BC 8-10 m/yr

1.7-7

Sulina

lspit1

Danube Delta

.5kyr

.BC

Chilia Delta

Initia

Tulcea

Razim Lake

2.000 BC 5-6 m/yr

9-7.200 BC 3-5 m/yr

St. George Delta 9-7.200 BC Coastline 100 AD

2-2.800 BC 8-9 m/yr

St. George

St. George Delta

Coastline 2.800 BC

Cosna- Sinoie Delta 3.550-2.500 BC

Fig. 1.9 The paleogeological evolution of the Danube Delta, processing after Panin (1997)

12

1 The Black Sea Basin, Physical–Geographical Conditions

deltaic lobes (Fig. 1.10a), and the chronological framework of the deltaic lobes, where the colors indicate the main Danube branch that built the lobes: dark blue— Danube; blue (and cyan)—Sf. Gheorghe; green—Sulina; red and magenta—Chilia, dotted lines indicate time intervals with low river discharge (Fig. 1.10b) [24, 25]. Based on the studies of Fedorov (1963, 1978), the sea level variation in the Pleistocene–Holocene was the following: the highest level was 600,000 years ago, corresponding to the maximum of the Ceauda transgression, two peaks, approximately 400,000 years ago and 300,000 years ago, respectively, corresponding to the transgression of the Old Euxinus, two peaks 100,000 years ago, corresponding to the Karangat transgression and a peak corresponding to the Holocene transgression (Fig. 1.11) [21].

Fig. 1.10 (a) and (b) The evolution of the Danube Delta. Source: By courtesy of. Prof. Panin et al., The Northwestern Black Sea: climatic and sea-level changes in the late Quaternary, The Black Sea Flood Question, Changes in Coastline, Climate and Human Settlement, Springer, Dordrecht, The Netherlands, 2007 Source: By courtesy of Prof. Vespremeanu-Stroe et al., Holocene evolution of the Danube delta: An integral reconstruction and a revised chronology, Marine Geology No. 388, 2017 Thousand of years 600

500

400

300

200

100

0

50

100 Height [m]

Fig. 1.11 The Black Sea level in the Pleistocene–Holocene: 1. the sea level variation in the Pleistocene (in Fedorov’s opinion, 1978); 2. the calculated variation of the sea level in the Pleistocene. (Modified from Yesin, 1993)

1.3 Coast Evolution in Holocene 0

2

Actual sea level

0m 10 20 30 40 50 60 70 80 0m 10 20 30 40 50 60 0m 10 20 30 40 50 60 0m 10 20 30 40 50 60 70 80

1

Actual sea level

Actual sea level

Actual sea level

3

4

13 5

0

km

0m 10 20 30 40 50 60 70 80 0m 10 20 30 40 50 60 0m 10 20 30 40 50 60 0m 10 20 30 40 50 60 70 80

1

2

3

4

5

km

Actual sea level

Actual sea level

Actual sea level

Actual sea level

Fig. 1.12 The shelf evolution in the Pleistocene– Holocene. (Modified after Yesin, 1993)

The shelf evolution in the Pleistocene–Holocene, in Yesin’s opinion (1993), (Fig. 1.12) is [21]: 1. 2. 3. 4. 5. 6.

– Relief profile before Ceauda – Shelf profile after the first old Euxinian transgression – Shelf profile after the last old Euxinian transgression – Shelf profile after the Karangat transgression – Shelf profile after the euxinic transgression – Seafloor profile according to the seismic measurements

In the late 1990s, the rapid and catastrophic marine flooding of the Black Sea by the Mediterranean water (Ryan et al. 1997) was proposed. It took place about 7500 years BC According to the authors, the level of the Black Sea was high enough during the initial deglaciation for some fresh Pontic water to enter the Aegean Sea, but about 12,000 years BC, the retreat of the ice sheet led to temporary meltwater into the North Sea. Deprived of this incoming meltwater during the cold Younger Dryas beginnings approx. 11,000 years BC and under the influences of a drier and windier climate that lasted until 9000 years BC, the Black Sea experienced a new regression to 156 m. At the same time, the Mediterranean Sea level continued to

14

1 The Black Sea Basin, Physical–Geographical Conditions

rise at the same pace as the global ocean. This progressive increase finally reached the height of the Bosporus sill 7150 years BC and broke through, generating a massive torrent of saltwater into the Black Sea Basin [23]. This „Noah’s Flood” hypothesis proposed by Ryan and Pitman suggests that the event formed the historical basis for the biblical legend of Noah’s Flood [26].

1.4

Conclusions

Despite many complex interdisciplinary studies, the birth and geological evolution of the Black Sea is still a great enigma and currently arouses numerous scientific disputes. Nowadays, important scientists have developed three crucial scenarios related to the late glacial to Holocene rise in the level of the Black Sea: catastrophic [27], gradual [28], and oscillating [29]. Substantial arguments support all of these, but they are subject to well-founded scientific criticisms. It is up to future, elaborate scientific research undertaken in the Black Sea Basin to validate which of these theories is closest to historical reality. In Fig. 1.13, the Black Sea level variation according to different authors is presented [25]. In the last decade, there have been numerous relevant scientific studies regarding the geological evolution of the Black Sea Basin, carried out by scientists not only from the Black Sea coastal countries but also from around the world. A summary of the main conclusions of some recent studies, along with comments from the author, is presented below. For a better understanding of the different points of view of the authors regarding this particularly complex problem, I chose to use, in a less used way, longer quotations from the following scientific papers, to which I had access. The Black Sea [30] is a vast marginal sea surrounded by a system of Alpine orogenic chains, including the Balkanides–Pontides, Caucasus, Crimea, and North Dobrogea located to the south, northeast, north, and northwest, respectively. The Age (years BC) 90,000 80,000

70,000 60,000

Karangatian basin Sea level curve after Chepaliga, 1985 Marine environment Brackish environment Lacustrine environment

50,000 40,000 30,000

Marine water

20,000

10,000

0

Black Sea basin

Surozhian basin

0m Brackish Neo -Euxinian basin

Post-Karangatian or Pre-Surozhian basin

Sea level curve after Ryan et al., 1997

Fresh water

Sea level curve after data from Danube Delta and Romanian shelf Panin et al., 1983

-50 m

-100 m

-150 m Karangatian

Post-Karangatian

Surozhian

NeoHolocene Euxidian

Fig. 1.13 Black Sea level variation different scenarios [25]. (Modified after Panin et al., 2007)

1.4 Conclusions

15

Black Sea Basin represents a back-arc basin that opened during the Early Cretaceous–Early Paleogene northward subduction of the Neo-Tethys below the Balcanides–Pontides volcanic arc. Deeply reflective seismic studies (Finetti et al., 1988) indicate two extensional sub-basins. The Western Black Sea Basin opened in a relationship with the separation of the Istanbul zone from the Moesian Platform. A Late Barremian–Early Albian rifting phase was followed by Cenomanian to Maastrichtian significant subsidence and emplacement of oceanic crust. The Eastern Black Sea Basin formed in response to Late Paleocene rifting, followed by Middle Eocene emplacement of oceanic crust (Robinson et al., 1996). These two major sub-basins are separated by a large continental uplifted block, i.e., the Mid-Black Sea Ridge (or Andrusov Ridge, Finetti, et al., 1988), which is delimited westwards by a major sinistral strike-slip fault system, which is the southeastern continuation of the Odesa Fault (or West Crimea Fault (Fig. 1.14) [31]. In 2006, Goriacikin and Ivanov (2016), in their book Black Sea Level: Past, Present, Future, concluded as follows (upon the results of large-scale geological research conducted along with the coastal areas and on the continental shelf) distinguish between the three main periods of evolution of the Black Sea level regime [32]: – A minimum regression between 20 and 16 thousand years ago, with the sea level at 60 m. – An intermediate phase between 16 and 6 thousand years ago, related to the Holocene melting, characterized by a sea-level rise up to 3.5 to 4 m. – A maximum in the last 6000 years, characterized by a transgression when the present-day sea level is reached.

Fig. 1.14 Sketch of the Black Sea Region Geological Structure [31]. (Source: By courtesy of Prof. N. Panin, Marine Research Infrastructure in the Black Sea Region, according to Dinu et al., 2005—the Tectonic map of the Black Sea region. (Modified after Gorür, 1988))

16

1 The Black Sea Basin, Physical–Geographical Conditions

Legend: 1. Orogene overthrust front 2. Gravitational faults of the rift 3. Major strike-slip faults 4. Major faults 5. Limits of depressions and/or ridges 6. Zone without granitic crust 7. Thinned crust

NKLD: North Kilia Depression SSR: Suvorov-Snake Island KD: Nijna-Kamciisk Depression KR: Kramski RidgeSCO: South Crimea Orogen AR: Azov Ridge SD: Sorokin Depression HD: Histria Depression KTD: Kerci-Taman Depression TB: Tuapse Basin WBS: Western Black Sea NKD: North Kilia Depression EBS: Eastern Black Sea ATD: Adjaro-Trialet Depression BD: Balkanides Depression

– In the interval 18 to 8 thousand years BP, the Black Sea level rose steadily at a rate of ca 9–10 mm/year. During this time interval, the sea level rose from 85 to 25 m. – In the interval 8 to 5 thousand years BP, the sea level continued to rise at a lower annual rate. At certain periods, the sea level exceeded by about 2 m the presentday sea level. – The Black Sea phases of the sea-level change are: – The Black Sea new transgression, which took place about 2–3 thousand years BC, when the sea level reached the value of + (3–4) m above the present-day level – The Phanagorian regression, which took place between 2500 and 1000 BC, when the sea level fell to 3 m compared to the present one – The present-day transgression, which began in the twentieth century; – In the last 6000 years, the sea level oscillations had 3000 years, and the Black Sea level deviated from the present day, with 5 to +2 m, at a 3–4 mm/year speed. – As for Noah’s Flood, it occurred 7600 thousand years ago, as a result of a catastrophic earthquake that allowed Marmara water to penetrate the Black Sea. Shortly, the Black Sea rose by more than 100 m, flooding large coastal areas. In 2007, the study The Controversy Over the Great Flood Hypotheses in the Black Sea in Light of Geological, Paleontological, and Archaeological Evidence (Yanko-Hombach, et al., 2007) ends with the following conclusions briefly: at the Last Glacial Maximum (LGM), the Black Sea was a semi-fresh to brackish (but never freshwater) lake of Neoeuxinian age with a level 100 m below present. At the time, it was isolated from both the Caspian Sea and the Sea of Marmara. In the warming climate of about 17 ky BP, multiple factors increased the level of the lake to

1.4 Conclusions

17

20 m. Excess semi-fresh water from the lake spilled into the Sea of Marmara, which conducted the discharge into the Mediterranean. After about 9.8 ky BP, the level of the Black Sea never again dropped below the 50 m isobath, nor did it exhibit a maximum amplitude of fluctuation greater than about 20 m. The brackish lake was ultimately transformed into a semi-marine basin by a process that was neither rapid, nor gradual, nor catastrophic. Instead, it occurred in an oscillating manner, permitting periodic immigration of Mediterranean organisms into the Pontic basin. The first wave of immigration occurred at about 9.5 ky BP, a date much earlier than that proposed in the Early Holocene Flood scenario. The recolonization was slow at the beginning and became more pronounced by 7.2 ky BP, finally reaching its climax between 6.0 and 2.8 ky BP. Most likely, the initial post-glacial connection between the Black Sea and the Sea of Marmara was not through the Bosphorus Strait. An alternative route through Izmit Bay, Sapanca Lake, and the Sakarya River could have existed at the time. During the last 10,000 years, the water level in the Black Sea rose gradually, but in an oscillating manner, occasionally rising higher but eventually attaining its present situation. Although the Late Pleistocene Flood scenario has a much stronger geological and paleontological basis in evidence, reliable archaeological indications do not yet demonstrate that such flooding had a major impact on human groups of the time. Barring new and more compelling data, one must conclude that the Early Holocene Black Sea “Flood” represents a contemporary legend. The intriguing geological and archaeological history of the Pontic region deserves more research and will eventually reward exploration with discoveries, but media portrayals of a catastrophic turning point in human history on the scale of the biblical deluge have diverted serious attention away from its real geographical and cultural importance. The public perception that “Noah’s Flood” happened there is not supported by any scientific evidence [33]. Today, as in recent years, these questions are topical (Yanko-Hombach et al., 2007): Was the Black Sea inundation the source of a flood myth, specifically one that inspired western Asiatic peoples to the beliefs that inspired the account of Noah in Genesis? For both its advocates and detractors, the “Noah’s Flood Hypothesis” of Ryan et al. has been a stimulus to further inquiry, made more productive by having a target to consider for the investigation. That the target involved considerable inspiration to the popular imagination just made the inquiry more intense and compelling. For what more could one ask in a scientific controversy? [32]. After 10 years (2017), Yanko-Hombach et al. in Geological and Geomorphological Factors and Marine Conditions of the Azov-Black Sea Basin and Coastal Characteristics as They Determine Prospecting for Seabed Prehistoric Sites on the Continental Shelf concluded: [33] our latest multidisciplinary study of geological material recovered in areas of the northwestern, northeastern, and southwestern Black Sea shelf confirm our previous data: 1. The level of the Late Neoeuxinan Lake before the Early Holocene Mediterranean transgression stood around 40 m BSL, but not 100 m BSL or more, as suggested by advocates of the catastrophic/rapid/prominent flooding scenario.

18

1 The Black Sea Basin, Physical–Geographical Conditions 1. Microfossil data examined from multiple shelf sites show that at all times, the Neoeuxinan lake was brackish with a salinity of about 7 psu before the Initial Marine Inflow (IMI) and Mediterranean transgression. 2. By 8.9 ka BP, the outer Black Sea shelf was already submerged by the Mediterranean transgression. An increase in salinity took place over 3600 years, with the rate of marine incursion estimated on the order of 0.05 cm/year to 1.7 cm/year. 3. The combined data from sedimentological characteristics and microfossil salinity evidence establish that the Holocene marine transgression was of a gradual, progressive but oscillating nature [33].

In The Black Sea Environment, Kostianoy and Kosarev (2008) concluded: in the recent history of the Black Sea, a series of transgressive stages with particular types of hydrological conditions, faunistic assemblages, and coastal settings are recognized, such as the Chaudian, the Old Euxinian, the Uzunlarian, the Karangatian, the Tarkhankutian, the New Euxinian, and the Black Sea stages, briefly characterized as [7]: – The Chaudian transgression stage began in the early Pleistocene and terminated at the beginning of the Middle Pleistocene. – The Karangatian transgression stage coincided with the major (Riss–Wurmian) interglacial period of the Russian Plain (approx. 0.12–0.07 million years), duration at 70–50 thousand years. – The Tarkhankutian transgression stage represents the final stage of the existence of a Mediterranean-type basin in the second half of the Late Pleistocene, evolution about 0.5 million years. – The New Euxinian transgression stage developed in a stadial mode: – 15.0–12.500 years BC (Enikal stage), the level in the basin rose by 20 m, later fell down to 45 m – 11.000 years BC (the New Euxin stage proper), the level sharply rose to its maximum at about 20 m – The Black Sea (Flandrian) transgression stage, 7–8.000 years BC, was caused by the breach of Mediterranean waters, which filled the basin. In the last decade, scientific research in the paleogeology of the Black Sea has continued, finalized by some remarkable scientific articles. In the article Heterogeneous Structure of the Lithosphere in the Black Sea from a Multi-disciplinary Analysis of Geophysical Fields [34], in 2015, Starostenko et al. show that the opening and evolution of the Black Sea Basin have been disputable for many decades due to lack of adequate information on peculiarities of its deep structure. The OSO is the Precambrian tectonic disruption in the crystalline crust of the Black Sea; with it tectonic activity is continuing up to now. Obliquity of the rifts in the Western and Eastern Black Sea Basins demonstrates that these depressions were diachronous formed as two separate tectonic units with their post-rift autonomous and individual histories. The An Ridge is formed by the stretched continental crust, and the Ar Ridge is composed of the thickened ocean crust. The

1.4 Conclusions

19

Sin Trough resulted from the Late Miocene incipient dextral strike-slip motion of the North Anatolian Fault [35]. About the evolution of the Black Sea Basin in the last 10,000–12,000 years, Romanian researchers Caraivan et al. (2015) show that the cyclic changes of the Black Sea level during the Upper Quaternary induced drastic changes in the shoreline. The oldest marine deposits found in the drill holes made on the barrier beaches and in the cores taken on the shelf belong to the “Surozhian strata” (MIS 3) when the Black Sea level was 10 m below the actual one. During LGM (Last Glacial Maximum) (MIS 2), the shoreline retreats eastwards, reaching the 100–120 m isobaths, therefore the recent shelf, and Bosporus-Dardanelles straits remained exposed. This process enabled migration of the prehistoric human communities from Asia to Europe, which was established on the newly created alluvial plain from the Black Sea western shelf. The Holocene Transgression (MIS 1) determines sea level rise up to the actual one and probably higher. The mean rate of sea-level rise was about 20 cm in 100 years, probably higher in the Atlantic Period (Climatic Optimum, 4800–7400 y BP) (Fig. 1.15) [35]. Under the pressure of these environmental changes, the Neolithic settlements slowly retreated to the Dobrogean river mouths. That’s why traces of these communities are found mainly along the borders of coastal lakes, and explains the scarcity of the Neolithic settlements on the adjacent shelf [36], which undermines the theory developed by Ryan et al., and are approaching or confirming the opinions of those who speak of a somewhat slow and predictable evolution of the recent geological history of the Black Sea.

Fig. 1.15 The evolution of the Black Sea basin in the last 10,000-12,000 years. (Source: By courtesy of dr. Caraivan et al., Holocene landscape changes and migration of human communities in the western part of the Black Sea (Mamaia Lake area), IGCP 610 Third Plenary Meeting and Field Trip, Astrakhan, Russia, 22–30 September 2015 [36])

20

1 The Black Sea Basin, Physical–Geographical Conditions

In The Black Sea Basins Structure and History: New Model Based on New Deep Penetration Regional Seismic Data. Part 2: Tectonic History and Paleogeography (Nikishin et al., 2015), a new litho-stratigraphy scheme has been compiled for the Western Black Sea Basin and a new geological history scheme from the Middle Jurassic till the Neogene is suggested for the entire Black Sea Region. Continental rifting manifested itself from the Late Barremian to the Albian, while the time of opening of the basins with oceanic crust was from the Cenomanian till the mid-Santonian; origination of the Western and Eastern Black Sea Basins took place almost simultaneously. During the Cenozoic time, numerous compressional and transpressional structures were formed in a different part of the Black Sea Basin. It is shown that in the Pleistocene-Quaternary time, turbidities, mass-transport deposits, and leveed channels were being formed in the distal part of the Danube Delta (Fig. 1.16) [36]. In 2016, Goldberg, et al., in their paper The Timing of the Black Sea Flood Event: Insights from the Modeling of Glacial, suggest that a flood event at 9 ka implies that the elevation of the sill was lowered through erosion by 14–21 m during, and after, the flood. In contrast, a flood event at 7 ka suggests an erosion of 24–31 m at the sill since the flood (Fig. 1.17) [37]. In 2016, Romanian scientists Oaie, Seghedi, and Rădulescu show that the Black Sea is a Cretaceous-Tertiary basin surrounded by orogenic belts derived through the closure of the Tethys ocean: the Caucasus to the east, the Pontides to the south, the Srednogorie and Balkans to the west, and the North Dobrogea Orogen and South Crimea Fold belt to the north, formed in extensional, backarc setting, in

Fig. 1.16 New lithostratigraphy scheme for the Western Black Sea Basin [37]. (By courtesy of Prof. A., M. Nikishin)

1.4 Conclusions 0

21 Relative Sea Level RSL at time of flood (m) 40 m flood

-10 30 m flood -20

-30

-40

-50 100m flood

Time of Flood (years ago)

-60 13.000

12,000

11,000

10,000

9,000

8,000

7,000

Fig. 1.17 The timing of the Black Sea flood event. (Source: modified after Goldberg et al., The timing of the Black Sea flood event: Insights from the modeling of glacial, Earth and Planetary Letters, Volume 452/suppl/C, 2016 [37])

connection with the closure of the Tethys by northward subduction, and several issues remain controversial: the timing of opening, mechanisms of basin formation, and crustal affinities (Fig. 1.18) [38]. The scientist Kalafat (2017), in his paper Seismicity and Tectonics of the Black Sea [39], shows the connection between earthquakes in the Black Sea region and the geological evolution of this basin: the important earthquakes in the region (Mw > 6.0) generally occurred in southeastern Crimea, Georgia mainland, offshore of Bulgaria, and offshore of Bartın (coast of the Black Sea). The depths of the earthquakes were generally between 10 and 35 km. The largest earthquakes occurred at the boundaries of the Black Sea. The mechanism of the large events at the margins indicates an oblique deformation of the region combined with North-South compression and East-West shear. The deep basin of the Black sea is relatively aseismic. The earthquakes in the central part of the Black Sea are associated with the ridges oriented in SE-NW directions (Fig. 1.19) [39]. In Compilation of Geophysical, Geochronological, and Geochemical Evidence Indicates Rapid Mediterranean-Derived Submergence of the Black Sea’s Shelf and Subsequent Substantial Salinification in the Early Holocene (Yanchilina et al., 2017), the conclusions are: the evidence in the form of stable isotopes, radiocarbon ages, 87Sr/86Sr measurements, and reflection profiles from shelf cores on the Ukrainian, Romanian, Bulgarian, and Turkish margins allow the evaluation of four competing hypotheses regarding the reconnection of the Black Sea to the Mediterranean and thus the global ocean following the last ice age. Three of the hypotheses are inconsistent with the observations. The evidence supports the fourth

22

1 The Black Sea Basin, Physical–Geographical Conditions

Fig. 1.18 Schematic map showing the major tectonic units and morphological structures of the Black Sea. (Modified after Robinson et al., 1996). Abbreviations: PDD Pre-Dobrogea Depression, NDO North Dobrogea Orogen, CD Central Dobrogea, SD South Dobrogea, SCF South Crimea Fold Belt, V Vrancea zone, WP West Pontides, CP Central Pontides, EP East Pontides, NAF North Anatolian Fault, EBS East Black Sea Basin, WBS West Black Sea Basin [38]. (By courtesy of Dr. V. Radulescu)

Fig. 1.19 Fault mechanisms in the Balck Sea region (1968–2015) [39]. (By courtesy of Prof. D. Kalafat)

1.4 Conclusions

23

hypothesis indicating that sudden submergence of the Black Sea shelf and subsequent rapid salinification of its water at 9300 calendar years BP was a consequence of the inflow of Mediterranean water. The transformation from the lake to the sea is recorded in coquina where successive appearances and disappearances of mollusks with 14C ages and isotopic compositions are indicative of a greater and greater contribution of water from the Mediterranean to the surface lake layer of ~100–200 m. The continuing sea-level rise that followed the initial submergence took place in tandem with the external global ocean [40]. In the paper Late Pleistocene Environmental Factors Defining the Black Sea, and Submerged Landscapes on the Western Continental Shelf (Lericolais, 2017), the conclusion is: aside from the controversy about the conditions of the last reconnection of the Black Sea, these recent syntheses have improved the chronology of the last reconnection, indicating that it occurred around 9000 years ago. This finding shows that the reconnection was not related to catastrophic drainage of the ice-dammed Lake Agassiz. Moreover, now it is possible to confirm that the replacement of lacustrine by marine biota needed almost 1000 years, the time required for the onset of the two-way flow circulation currently observed in the Sea of Marmara gateway. These results also suggest that the level of the isolated Black Sea was below the former Bosporus sill depth [41]. In Geomorphic Evidence for Active Tectonic Deformation in the Coastal Part of Eastern Black Sea, Eastern Pontides, Turkey, Softa et al., 2018, bring geomorphic evidence for active tectonic deformation in the coastal part of Eastern Black Sea, through which the Eastern Pontides have been gradually uplifting in the “push-up” geometry of the Black Sea Fault and the Borjomi-Kazbegi faults linked with the North Anatolian Fault since the Late Quaternary period (Fig. 1.20) [42]. A recent study, Age and Geodynamic Evolution of the Black Sea Basin: Tectonic Shreds of Evidence of Rifting in Crimea (Hippolyte et al., 2018), provides a new mapping and a fault kinematic analysis of graben structures in Crimea. The occurrence of olistoliths and debris-flow deposits in Crimea is related to extensional block faulting. Nannoplankton assemblages from the syn-rift sequence allow the dating of the extensional event to the Valanginian to Late Albian. Fault chronology indicates that extension predates the Cenozoic shortening events. Two successive directions of shortening are responsible for the uplift of the Crimean Mountains. The onset of compression is at the Paleocene–Eocene transition, like in the Pontides. That is also supported by the crystal structure of the Western Black Sea Basin, which suggests that the normal faults of Crimea connect to low-angle crustal detachments. This coincidence of timing suggests that the compressional deformation along the northern margin of the Black Sea results from the continental collisions that occurred to the south of the Black Sea with the transmission of the compressional stresses through the cold lithosphere of the Black Sea Basin [43] (Fig. 1.21). In 2018, Simmons et al., in their Petroleum Geology of the Black Sea: Introduction, said: controversy and uncertainty continue to be key features of Black Sea geoscience. Several deep-water exploration wells have failed because of an inability to predict correctly reservoir presence and reservoir quality. This is true for both carbonate plays and siliciclastic plays. They put these questions, also: Does

24

1 The Black Sea Basin, Physical–Geographical Conditions

Fig. 1.20 A conceptual model for the Eastern Pontides, which demonstrates an active deformation zone and has a “push-up” geometry within the Black Sea Fault in the sea and the Borjomi-Kazbegi Fault on land in conjunction with the North Anatolian Fault at depth [42]. (By courtesy of Prof. M. Softa)

Fig. 1.21 Structural elements of the Black Sea Basin. (Modified from Hippolyte et al., 2018 [43])

1.4 Conclusions

25

the apparent lack of Late Cretaceous carbonate on the Andrusov Ridge suggest that both the Western Black Sea and Eastern Black Sea were rapidly subsiding at this time? This possibility appeals to the fundamental question regarding the relative timing of the opening of the Western and Eastern Black seas. Was this synchronous, or do they relate to completely separate phases of tectonic evolution? From the Oligocene onwards, the Black Sea and its constituent basins formed part of Paratethys, a remnant of the closure of Tethys. It lies at the southern margin of Laurasia, which formed the northern margin of Tethys. The basins of the Black Sea are extensional in origin related at least in part to the northwards subduction of strands of Tethys beneath Lauria but are surrounded by compressive belts. Crimea and Greater Caucasus, formed by the inversion of the Mezozoic Caucasus Basin in the Cenozoic, border the Black Sea to the north and east. A small basin, the Rioni, lies to the east in Georgia. The Balkanides and Pontides orogenic zones, formed from an accretion of terranes and island arcs, lie to the south and southeast [44] (Fig. 1.22). In their study Holocene Paleoecology and Paleoceanography of the SouthWestern Black Sea Shelf Revealed by Ostracod Assemblages, Williams et al., (2018) concluded that: the changes in the ostracod assemblages from one bioecozone to the next indicate that progressive environmental changes took place on the southwestern Black Sea shelf from at least 7500 cal year BP to the present. The first hint of

Fig. 1.22 Basement topography of the Black Sea Basins (after Nikishin et al. 2015) with key tectonic and depositional elements as mentioned in the text. 1, Polshkov Ridge; 2, Tindala-Midia Ridge; 3, Tomis Ridge; 4, Lebada Ridge; 5, St George Ridge; 6, Sevastopol Swell; 7, Lomonosov Massif; 8, Tetyaev Ridge; 9, Anapa Swell; 10, North Black Sea High; 11, South-Doobskaya High; 12, Gudauta High; 13, Ochamchira High; 14, Ordu-Pitsunda Flexure; 15, Rezovo-Limankoy Folds; 16, Kamchia Basin; 17, East Moesian Trough; 18, Babadag Basin; 19, Küre Basin [44]. (By courtesy of Dr. M. Simmons)

26

1 The Black Sea Basin, Physical–Geographical Conditions

changing conditions at ~7500 cal year BP lags the initial reconnection to the Mediterranean Sea through the Strait of Bosporus by ~2000 year, demonstrating that Black Sea salinity increased slowly and took that long to reach values tolerable to marine ostracod immigrants. Widespread colonization by Mediterranean species took even longer, ~3000 years from the time of the initial reconnection [45]. In an important study, Morphologic and Seismic Evidence of Rapid Submergence Offshore Cide-Sinop in the Southern Black Sea Shelf (Ocakoğlu et al., 2018), it is concluded that Multi-beam bathymetric and multichannel seismic reflection data obtained offshore Cide-Sinop have revealed important records on the latest transgression of the Black Sea for the first time, and these results indicate that offshore Cide-Sinop was once a terrestrial landscape that was then submerged. The interpreted paleo shoreline varies from 100 to 120 m. This variation can be explained by not only sea-level changes but also the active faults observed on the seismic section. The effective protection of morphological features on the seafloor is the evidence of abrupt submergence rather than gradual. Also, the absence of coastal onlaps suggests that these morphological features should have developed at low sea level before the latest sea-level rise in the Black Sea [46]. The study Late Pleistocene to Holocene Paleoenvironmental Changes in the NW Black Sea (Briceag et al., 2019) shows that numerous studies, between 2007 and 2019, bring arguments by which the hydrological evolution of the Black Sea is well reflected in ostracod assemblages, including during the Late Pleistocene to Holocene in the NW Black Sea. Numerous microfaunal studies providing new insights into past environmental conditions during the Late Pleistocene–Holocene has identified at 9600 a BP the first Mediterranean ostracod immigrants, between 8800 and 6700 a BP, a mixed Caspian and Mediterranean ostracod assemblage that points to sustained cohabitation, reflecting a gradual increase in bottom water salinity from 7% to 18%, and from 6800 a BP, the ostracod faunas become dominated by Mediterranean taxa [47].

1.5

Conclusions

The Black Sea is a natural inland water basin situated between Europe and Asia and has the aspect of a deep basin, oriented from west to east, stretching on approximately six degrees of latitude and five degrees of longitude, an intercontinental sea, being connected to the Mediterranean Sea through the Bosporus Strait and to the Azov Sea through the Kerch Strait. The actual shape of the Black Sea probably appeared about 40 million years ago, at the end of the Paleolithic period (Miocene, Mio-Pliocene), respectively, when the structural raises from Asia Minor detached the Caspian basin from the Mediterranean basin; the Black Sea gradually separated from the Caspian region about 25 million years ago. The subsequent geological evolution produced changes to the sea level and, associated with the action of the Ice Age glaciers, formed intermittent connections

References

27

with the Mediterranean basin (this phenomenon happened about 6–8 million years ago). The geological evolution of the Black Sea Basin in its recent history, with application to the hypothesis of Noah’s flood that would have quickly opened the connection with the Mediterranean Sea, and the development of the Black Sea in its form today, intensely debated in academia, and not only, is not on fully elucidated and approved in the international academic environment. There are currently many solid scientific papers that do not share this point of view and describe the formation of the current Black Sea as a geological long process. The main conclusion, drawn from the study of classical and recent bibliographic sources, of which we have presented consistent fragments so that they can be correctly understood, is that the geological evolution of the Black Sea is of enormous scientific interest to many scientists and that it was not said, by far, everything that had to be said in this matter, and so international, multidisciplinary collaboration is needed to decipher all the mysteries of this magnificent place.

References 1. ***https://www.un.org/sustainabledevelopment/wp-content/uploads/2017/05/Ocean-factsheet-package.pdf. Accessed 06.03.2018 2. ***Review of Maritime Transport, UNCTAD, Geneva, Switzerland, 2019 3. ***Review of Maritime Transport, UNCTAD, Geneva, Switzerland, 2020, https://unctad.org/ system/files/official-document/rmt2020_en.pdfrmt, 2020. Accessed 15.11.2020 4. ***https://www.bsnn.org. Black Sea NGO Network html. Accessed 21.01.2020 5. ***Expert Group of the Blue Growth Initiative for Research and innovation in the Black Sea, Black Sea Strategic Research and Innovation Agenda, 2019 6. Boşneagu R (2004) Geographical conditions influence of the maritime routes in the Black Sea Basin (Western sector), Cartea Românească, Publishing House Bucharest, Romania, (in Romanian) 7. Kostianoy AG, Kosarev AN (eds) (2008) The Black Sea environmental. Springer, Berlin/ Heidelberg 8. Zaitsev Y (2008) An introduction to the Black Sea ecology. Smil Editing and Publishing Agency Ltd., Odesa 9. Boşneagu R et al (2018) Black Sea – geopolitical, economic, social and military importance. J Phys Confer Ser 1122(1):012006. https://doi.org/10.1088/1742-6596/1122/1/012006 10. Stanchev E et al (2011) Determination of the Black Sea area and coastline length using GIS methods and Landsat 7 satellite images, GEO-ECO-Marina 17/2011 11. Yu P et al (2002) The Back Sea an oxygen-poor sea. In: Europe’s biodiversity-bio geographical regions, and sea. European Environment Agency 12. Bondar C (2011) Black Sea Oceanography, V. A. Ivanov, V.N. Belokopatov, Institute of Marine Hydrophysics, National Academy of Sciences of Ukraine, Sevastopol, 2011, Book Review, GEO-ECO-Marina 20/2014 13. Dimitrov D, Dimitrov T (2004) The Black Sea, the Flood, and the Ancient Myths. Varna, Slavena 14. Saulea E (1967) Historical Geology. Didactic and Pedagogical Publishing House, Bucharest 15. ***GEF – the Black Sea Environmental Programme – Romanian coastline of Black Sea, Value and preservation, Bucharest, 1995

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16. Şelariu O (1999) Continental platform from the Romanian sector of Black Sea, „Mircea cel Batran” Naval Academy Publishing House, Constanta (in Romanian) 17. Zaitsev Y, Mamaev V (1997) Marine biological diversity in the Black Sea, a study of change and decline, GEF Black Sea Environment Programme, vol 3. UN Publications, New York, pp 1–3 18. ***The Black Sea in the Romanian coastline area, The Hydrological Monography, Bucharest, 1973. 19. Ross DA (1974) Bathymetry, and Microtopography of the Black Sea. The Black Sea –Geology, Chemistry and Biology, AAPG, Memoir 20 20. Panin N et al (1971) Bathymetric research on the Black Sea shelf. Researches Studies of Geology, Geophysics, Geography, The Geophysics, Volume 15 21. Yesin NV (1993) Transformation of the Black Sea coast and shelf by wave erosion in Pliocene – Pleistocene. In: Kostyan R (ed) Coastlines of the Black Sea. American Society of Civil Engineers, New York 22. Panin N et al (1997) On the geomorphologic and geologic evolution of the River Danube-Black Sea interaction zone. GEO-ECO-Marina 2:31–25, Bucharest-Constantza 23. Rădulescu M (1988) Black Sea coast evolution between Sfîntu Gheorghe and Capul Midia. Dissertations session I.M.M.B., Constanta (in Romanian) 24. Vespremeanu-Stroe A et al (2017) Holocene evolution of the Danube delta: an integral reconstruction and a revised chronology. Mar Geol 388:38–61 25. Panin N, Popescu I (2007) The Northwestern Black Sea: climatic and sea-level changes in the late Quaternary. In: The Black Sea flood question, changes in coastline, climate and human settlement. Springer, Dordrecht 26. Yanko-Hombach V et al (2007) Controversy over Noah Flood in the Black Sea: geological, and foraminiferal evidence from the shelf. In: The Black Sea flood question, changes in coastline, climate and human settlement. Springer, Dordrecht 27. Ryan WBF et al (2003) Catastrophic flooding of the Black Sea. http://www.meteo.mcgill.ca/ ~tremblay/Courses/ATOC530/Ryan.et.al.,AnnualReviewEPS.2003.pdf 28. Hiscott RN (2007) A gradual drowning of the southwestern Black Sea shelf: evidence for a progressive rather than abrupt Holocene reconnection with the eastern Mediterranean Sea through the Marmara Sea Gateway, https://www.ucl.ac.uk/EarthSci/people/m-kaminski/ reprints-pdfs/HiscottQI.pdf 29. Yanko-Hombach V (2007) Preface, the Black Sea flood question, changes in coast line, climate and human settlement. Springer, Dordrecht 30. Dinu C et al (2005) Stratigraphic and structural characteristics of the Romanian Black Sea shelf. Tectonophysics 410:417–435, www.elsevier.com/locate/tecto, 2005. Accessed 12.24.2018 31. Panin N (2005) Marine Research Infrastructure in the Black Sea Region, after Dinu et al., 2005 – the Tectonic map of the Black Sea region (Modified after Gorür, 1988) 32. Hombach -Yanko V et al (2007) Controversy over the great flood hypotheses in the Black Sea in light of geological, paleontological, and archaeological evidence. Q Int 167–168:91–113, Available from: https://www.researchgate.net/publication/223177419_Controversy_over_the_ great_flood_hypotheses_in_the_Black_Sea_in_light_of_geological_paleontological_and_ archaeological_evidence. Accessed 12 Feb 2020 33. Yanko-Hombach V et al (2017) Chapter 16: Geological and geomorphological factors and marine conditions of the Azov-Black Sea Basin and coastal characteristics as they determine prospecting for Seabed prehistoric sites on the continental shelf. In: Flemming NC, Harff J, Moura D, Burgess A, Bailey GN (eds) Submerged landscapes of the european continental shelf: quaternary paleoenvironments, 1st edn. Wiley. Published 2017 by John Wiley & Sons Ltd, https://www.Researchgate.net/publication/318199054_Geological_and_Geomorphological_ Factors_and_Marine_Conditions_of_the_AzovBlack_Sea_Basin_and_Coastal_Characteris tics_as_They_Determine_Prospecting_for_Seabed_Prehistoric_Sites_on_the_Continental_ Shelf

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34. Starostenko VI et al (2015) Heterogeneous structure of the lithosphere in the Black Sea from a multidisciplinary analysis of geophysical fields. Geofizicheskiy Zhurnal 37:3–28. http:// journals.uran.ua/geofizicheskiy/article/view/111298/106279 35. Caraivan et al (2015) Holocene landscape changes and migration of human communities in the western part of the Black Sea (Mamaia Lake area), IGCP 610 Third Plenary Meeting and Field Trip, Astrakhan, Russia 36. Nikishin AM et al (2015) The Black Sea basins structure and history: new model based on new deep penetration regional seismic data. Part 2: tectonic history and paleogeography. Mar Pet Geol 59:656–670 37. Goldberg SL et al (2016) The timing of the Black Sea flood event: insights from modeling of glacial. Earth Planet Lett 452:178–184, https://www.sciencedirect.com/journal/earth-andplanetary-science-letters/vol/452/suppl/C 38. Oaie G et al (2016) Natural marine hazards in the Black Sea and the system of their monitoring and real-time warning. Geo-Eco-Marina 2016:5–28, https://www.geoecomar.ro/website/ publicatii/Nr.22-2016/01_OAIE_2016.pdf 39. Kalafat D (2017) Seismicity, and Tectonics of the Black Sea. Int J Earth Sci Geophys 3(1):11 40. Yanchilina AG et al (2017) Compilation of geophysical, geochronological, and geochemical evidence indicates rapid Mediterranean-derived submergence of the Black Sea’s shelf and subsequent substantial salinification in the early Holocene. Mar Geol 383:14–34, https:// www.sciencedirect.com/science/article/pii/S002532 2716 302961?via%3Dihub 41. Lericolais G (2017) Chapter 17: Late Pleistocene environmental factors defining the Black Sea, and submerged landscapes on the Western Continental Shelf. In: Flemming NC, Harff J, Moura D, Burgess A, Bailey GN (eds) Submerged landscapes of the European continental shelf: quaternary paleoenvironments. Wiley-Blackwell, Hoboken. https://doi.org/10.1002/ 9781118927823.ch17, http://archimer.ifremer.fr/doc/00391/50264/ 42. Softa M et al (2018) Geomorphic evidence for active tectonic deformation in the coastal part of Eastern Black Sea, Eastern Pontides, Turkey. Geodinamica Acta 30(1):249–264 43. Hippolyte JC et al (2018) Age and geodynamic evolution of the Black Sea Basin: tect onic evidences of rifting in Crimea. Mar Pet Geol Elsevier 93:298–314 44. Simmons MD et al (2018) Petroleum geology of the Black Sea: introduction. Geol Soc Lond Spec Publ 464:SP464.15. https://doi.org/10.1144/SP464.15 45. Williams LR et al (2018) Holocene paleoecology and paleoceanography of the southwestern Black Sea shelf revealed by ostracod assemblages. Mar Micropaleontol 142:48–66 46. Ocakoğlu N et al (2018) Morphologic and seismic evidence of rapid submergence offshore Cide-Sinop in the southern Black Sea shelf. Geomorphology 311:76–89 47. Briceag A et al (2019) Late Pleistocene to Holocene paleoenvironmental changes in the NW Black Sea. J Q Sci 34(2):87–100

Chapter 2

The History of Research Conducted in the Black Sea

Abstract From early antiquity, the Black Sea coast’s natives, Phoenicians, Greeks, and later, Romans, Byzantines, Ottomans, Vikings, Venetians, Genoese sailors, and others undertook expeditions along the coasts and of the Black Sea for exploration and commercial and military purposes. The systematic exploration of the Black Sea area begins in the nineteenth century and continued in force in the twentieth and twenty-first centuries. Today in the Black Sea, there are many international and national institutions whose main responsibilities are scientific research on geology, mineral, energy, and living resources, as well as their exploitation possibilities, navigation, seaborne trade, economy, politics, and geopolitics, ecology, archeology, and so on. For these, considerable financial, material, and human resources are allocated, national and international scientific and economic research programs have been and are being carried out, in which numerous research vessels, and an increasing number of researchers participate annually. It can be said that the interest in Black Sea research is special and growing, both for the coastal states and for the international scientific, political, and economic environment. Keywords Black Sea · History · Research In the area of the Black Sea, the first traces of navigators are of Phoenicians, followed by those that resulted from the Greek colonization, this phenomenon developing beginning in the seventh century BC [1]. One may say that the action of the ancient Greeks to found colonies at Pontus Euxinus was preceded and accompanied by the first research regarding its coasts, as well. In ancient times, many scholars, among which we remember Herodotus, Plinius the Younger, Ptolemaeus, etc. wrote about Pontus Euxinus (location, name, history, inhabitants, customs, etc.). From this period, an essential activity of Black Sea knowledge is mentioned, due to the sea periplus undertaken by Arrianus, the Roman governor of Cappadocia, during the reign of Hadrian. That activity was materialized in a report on the navigation from Pontus Euxinus, where all the ports and characteristics of the littoral are enumerated in detail, subsequently being quite precisely reproduced on the map of Ptolemaeus (34 AD) [2].

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_2

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32

2.1

2

The History of Research Conducted in the Black Sea

Black Sea Research in the Nineteenth Century

The systematic exploration of the Black Sea area begins in the nineteenth century, with the French-Russian expedition of 1820, the result being the description of the coasts. A step by step evolution of the research in the Black Sea area beginning with the second part of the seventeenth century is synthesized as follows [3–5] (Table 2.1): Table 2.1 Research in the Black Sea (seventeenth to twentieth centuries) Period 1696

1820

The leaders of the research expeditions The travel of Peter I’s ambassador to Constantinople

1825–1836

The French-Russian expedition E. P. Manganari

1853–1856

Commander Spratt

The second part of the nineteenth century

Kumani, Zarudnyi, Miakyshev, Andreev, Ivanovski

1872 1881–1882

Admiral S. O. Makarov

1890–1891

I.B. Spindler and F.F. Wrangel

1922–1928

N. Knipovich

1923–1927 1928–1936

I.M. Sokalski V.A. Snezhynsk

1949

The expedition of „Vityaz” research vessel

The result of the research The first measurements of the water’s depth Based on the measurements as mentioned earlier, in 1701, the first map containing the depths in the proximity of Crimea and bosphorus appears The Black Sea coast description In 1841, the Pilot Book appeared In 1845, an atlas of maps appeared In 1850, an atlas of hydrographical maps by E. T. De Marigny appeared In 1851, the map of the Black Sea, edited by the British Admiralty appeared Measurements of great depth between Bosphorus and Sevastopol In 1861, the map by Delesse appeared In 1871, the pilot Book appeared In 1845, an atlas of maps appeared The first marine biological station in Odessa The currents’ presence in the area of Bosphorus Strait Measurements of great depth Drawing up of some maps (the map from 1899 contains the isobaths of 100, 500, 1200 fathoms) The establishment of the fish resources in the Black Sea seabed Hydrology studies The drawing up of the Black Sea bed’s relief In 1934, the drawing up of the map at 1:750,000 scale In 1936, the drawing up of the map at 1:500,000 scale In 1958 the work “The Geological Structure and the History of the Black Sea” appeared The first continuous depth records

2.2 Black Sea Research in the Twentieth Century

2.2

33

Black Sea Research in the Twentieth Century

The scientific research of the Black Sea increased and diversified after the fifth decade of the twentieth century. The representatives of the coastal states and some international organizations (the National Institute for Marine Research and Development “Grigore Antipa” Constanţa, the National Institute for Marine Geology and Geoecology – GeoEcoMar, Bucharest-Constanta; the Institute of Oceanology, Varna; the Institute of Fishery Resources, Varna; the Institute of Marine Sciences, Erdemli; the Institute of Marine Science and Technology, Izmir; the State University from Tbilisi,;the „P.P. Shirshov” Institute of Oceanology; Moscow; the South Subsidiary of the „P.P. Shirshov” Oceanology Institute, Gelendzhik; the Sevastopol Institute of Marine Hydrophysical; the „A.O. Kovalevski” Institute of Biology of Southern Seas Sevastopol; the Ukrainian Scientific Centre of the Ecology of Sea Odesa; the Institute for Fishery Oceanography Kerch), etc. participated in these kinds of research. Therefore, it can be underlined that the systematic scientific research activity performed by the coastal states has been very difficult, beginning with the first years of the twentieth century. Russian researchers Zenov, Lebentsev, and Tehey (1911–1912) initiated the first research on the Bulgarian coast of the Black Sea, being followed by that of the Bulgarian researchers Karaoglanov and Kadjiev (1922–1928) [4]. In 1937 the Station of Biomarine Research Varna and the Ichthyology Station Sozopol was founded, and successively changed into the Institute of Fishing Resources (1954), the Institute of Oceanology and Fishing, and finally, into the Institute of Living Resources. In 1973, the Institute of Sea Research and Oceanology was founded, changed later on into the Institute of Oceanology, and from the Laboratory of Marine Geology, the Institute of Marine Geology was constituted, both institutions belonging to the Bulgarian Academy of Sciences. In 1975, the Laboratory of Marine Ecology and Sea Protection and the Laboratory of Sea Chemistry were founded, belonging to the Bulgarian Academy of Sciences. Other institutions that are performing marine research are the Laboratory for the Protection against Sea Pollution that belongs to the Maritime Transport Institute (1967) and the Hydrotechnics Laboratory that belongs to the Hydro and Aerodynamics Institute of the Bulgarian Academy of Sciences. As to the experiments and the expeditions organized by Bulgarian researchers, we mention the seismic research (1960), the sea expeditions 1969–1970 (Glumov), 1970–1971 (Zhgentsi), 1976–1979 (Vostretsov), the aeromagnetic research in the western basin of the Black Sea (1968), the geophysical research of the shelf (1971–1976), the geological and geophysical expeditions in cooperation with the Russian scientists 1974 (Purlichev), 1976 (Malovitsky), 1977 (Yonin), 1977–1978 (Kalinin), 1980–1981 (Geovekian), 1985–1990 (Dimitrov and Krischev), 1975–1990 (Dimitrov) [6]. Nowadays, the monitoring scheme implemented by the Institute of Oceanology of Bulgarian Academy of Sciences (IO-BAS) covers the Bulgarian economic zone, and sampling is carried out at least 4 times a year (Fig. 2.1) [7].

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The History of Research Conducted in the Black Sea

Fig. 2.1 Modified from The Institute of Oceanology of Bulgarian Academy of Sciences—monitoring scheme of the Bulgarian waters. Source: Ocean Sci., 8, 183–196, 2012, www. ocean-sci.net/8/183/2012/

Between 1963 and 1980, the Department for Navigation, Hydrography and Oceanography (DNHO) of the Turkish Navy performed 14 research cruises in the Black Sea (studies for temperature, salinity, chemistry, plankton, etc.). Also, the national research program of the Black Sea (Bl.S.N.P.), begun in 1987 and in which all the Turkish institutions of marine research participated, and the international expeditions in which Turkey participated in [8] must also be mentioned (Fig. 2.2). We mention some of the main expeditions of oceanographic research that offered the necessary data to reference studies of the Black Sea as follows: the American expedition of 1969, realized on board research vessel „Atlantis II” (Brewer, 1971; Degeans and Ross, 1974; Murray and Izdar, 1989); the expedition of 1975, realized on board the Research Vessel R/V „Chain” (Yannash and Karl), that assured the data basis for the following expedition, of 1988, made with the R/V „Knorr” Vessel (Murray and Izdar, 1989, Friederich, et al., 1990, Murray, 1991) [9], R/V „Glomar Challenger” in 1975 (Degeans and Ross). The many Turkish–German expeditions, out of which we mention those performed with R/V „Piri Reis” (1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991) and with R.V. „Vityaz,” (1985) [10] must be pointed out. The result of the intense research activity of the Black Sea, performed by the Soviet researchers between the years 1920, 1960–1970, was the achievement of over 100,000 oceanographic stations [11]. The programs of regional and international research, developed in the Black Sea after 1990, and to which the coastal states of the Black Sea, as well as other countries, have participated, are: Cooperative Marine Science Program for the Black Sea (COMSBLACK), 1991–1995; Ecosystem Modeling as a Management Tool for the Black Sea); Regional Program of Multi-institutional Co-operation – NATO-TUrkey – the Black Sea, 1994–1997; Black Sea Observation and Forecasting System (BSOFS), NATO/CCMS), 1998–2000; Wave climate along Turkish coasts/Black Sea (NATO TU waves); Investigation between the Danube River and

2.2 Black Sea Research in the Twentieth Century

35

Ukraine Odesa Azov Sea Kerch Romania

Russian Federation Novorosyisk

Sevastopol

Constanta 18

7

19

18

38

36

39

48

17

20

28

8

16

21

27

30

35

40

47

50

4

9

15

22

18

31

34

41

46

51

58

59

3

10

14

23

25

32

33

42

45

52

57

60

43

44

53

56

Varna

6 5

29

Bulgaria

11

2

13

Batumi

24

1

Istanbul

12

Georgia

49

Black Sea

Turkey

54

55

61 62

Samsun

Fig. 2.2 The oceanographic stations of the Turkish expeditions in the Black Sea. (Modified after Ünlüata and Izdar, 1991)

the northwestern Black Sea (EROS 2000), 1995–1997; Biogeochemical Interactions between the Danube River and the North-Western Black Sea (EROS 21), 1997–1998; Environmental Management and Protection of the Black Sea, GEF (UNEP, UNDP, World Bank) – The coastal states to the Black Sea, 1992–1998, together with its annual reports, and the newsletter „Save the Black Sea” [12]. By 1997, a marine geological survey (1:500,000 to 1:10,000) of the Black Sea shelf had been primarily completed by an Eastern European scientist. A methodology for this regional investigation was developed, and by using it, the paleoclimatic, tectonic, and sedimentary history of the Black Sea basin was investigated [13]. The Romanian research in the Black Sea began at the end of the nineteenth century, between 1885 and 1886, by performing the mapping of the seabed at the Sulina-Gura Portiţei area. Between 1897 and 1901, as a result of some topohydrographical works, the mapping of the Romanian littoral was realized, based on which the first Romanian navigation map of the Black Sea was drawn up, named „Commander Cătuneanu Map” and awarded the gold medal at the World Exhibition in Paris, 1902. Also, the first Romanian map of the Danube River, realized by the personnel of the Marine Children School in Galaţi, as a result of the student practice performed between 1882 and 1883 [14] must be mentioned. During the expedition of Grigore Antipa around the Black Sea, realized with the Romanian cruiser „Elisabeta” for nine months, prevailing biological research was performed, as well as hydrological observations, this research being materialized in the monograph The Black Sea, Oceanography, Bionomy, and General Biology (1941).

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The History of Research Conducted in the Black Sea

Among the great Romanian scientists, enjoying international recognition, who have had an essential contribution to the development of science in the marine field, first of all, we must mention Emil Racovitza, Grigore Antipa, and Ioan Borcea. Emil Racovitza is the first national delegate of Romania to ICSEM (International Commission for the Scientific Exploration of the Mediterranean Sea) (1925), the founder of the biospeleology (1920), participant in the Antarctic expedition onboard „Belgica” (1897), and member of the Romanian Academy. Grigore Antipa, a member of ICSEM (1927), is one of the first organizers of the research expeditions in the Black Sea (1893, 1894, 1895), author of many publications of marine biology, founder and director of the Natural History Museum in Bucharest (1893), member of the Romanian Academy and of the Oceanographic Institute in Paris, and expert counselor in the European Danube Commission [15]. In 1932, Grigore Antipa founded the Bio-oceanographic Institute in Constanța. At E. Racovitza’s generous recommendation, he also became the second national delegate of Romania to ICSEM. Professor Ioan Borcea, the pioneer of Romanian oceanography, founded the Marine Zoological Station in Agigea (1926), and completed with a chemical, biological laboratory in 1937 [16]. Constantin Brătescu is another important scientist in the biological field, who stands out, thanks to his geographical research (1922, 1928, 1933) about Dobrogea, the deltaic, and even marine areas. Among others, we point out Gheorghe Năstase (with works on marine morphology–hydrography, 1935), Radu Ciocârdel (with works about the seawater circulation, 1938) [17], Paul Bujor (1900), E.C. Teodorescu (1907), and Maria Celan (beginning in 1930, with works on benthic algology [18]. During the inter-war period, works were performed on the sea hydrography and hydrology by the Hydrographical Service of the Romanian Navy, the General Directorate of the Ports and Water Communications Ways. In 1933, the first registering tide gauge was installed in Constanţa. After the Second World War, marine research resumed, primarily the research on marine biology, but beginning with 1959, hydrographical and hydrological mappings in the Romanian territorial waters and on the shelf (1961–1969) were been performed. These were sporadically continued till 1978 and resumed after 1990, during national and international research campaigns. Among the numerous scientists who have dedicated their lives to various fields of oceanography, we must mention M.C. Băcescu, A.E. Pora, N. Panin, A.C. Banu, H.V. Skolka, C. Bondar, M.T. Gomoiu, A.S. Bologa and many others. Also, the coordination of the marine research activities supervised by A.S. Bologa (1989–1999), Gh. Şerpoianu (1990), as well as the work O. Şelariu in this field over decades as a researcher and teacher of must be credited. The activity of the Romanian institutions with a profile in the sea research [19] materialized beginning with the third decade of the twentieth century has gained momentum, through the national and international programs after the 1970s (Table 2.2):

2.2 Black Sea Research in the Twentieth Century

37

Table 2.2 The Romanian scientific institutions with a profile in sea research Char. no. 1. 2. 3. 4.

5.

6. 7.

8.

9.

10.

11.

Institution founder The Marine Zoological Station in Agigea Prof. I. Borcea The Bio-oceanographical Institute Dr. Gr. Antipa The Marine Research Station Dr. Grigore Antipa The Marine Biology Sector of the „T. Săvulescu” Biology Institute Prof. M. C. Băcescu The Oceanographical Station from Sulina of the Institute of Hydrotechnical Research Eng. C. Bondar The Marine sedimentology laboratory Acad. G. Murgeanu The Romanian Marine Research Institute Prof. M. C. Băcescu, Prof. E. A. Pora

Laboratory of marine geology and sedimentology Dr. N. Panin The Romanian Centre of Marine Geology and Geoecology Dr. N. Panin National Institute of Marine Geology and Geoecology GEOECOMAR Bucharest – Constanța Dr. N. Panin „Grigore Antipa” National Institute for Marine Research and Development Constanța Dr. S. Nicolaev

The foundation year 1926 1932

Affiliation Ministry of Education University of Iaşi Ministry of Agriculture

1945 1954

Romanian Academy

1960

The National Water Council

1964

Romanian Geology Institute National Council of Science and Technology and Ministry of Education Ministry of Agriculture and Food Ministry of Environment (from 1990) Ministry of Geology Geology and Geophysics Institute

1970

1968

1999

1999

The „Grigore Antipa” National Institute for Marine Research and Development (NIMRD) (going by this name since 1999) was founded at Constanța in March 1970 under the name Romanian of Marine Research Institute, by the unification of some marine research profile units [20], among which: the Marine Zoological Station „Prof. Ioan Borcea” from Agigea, and the Bio-oceanographic Institute. The institute’s activity materialized in many studies and various research, not only coastal sedimentology and morphodynamics, marine hydrology, marine chemistry and biochemistry, marine biology and microbiology, marine ecology, and radioecology

38

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The History of Research Conducted in the Black Sea

Fig. 2.3 The marine pollution monitoring network stations on the Romanian coastline modified after “Grigore Antipa” National Institute of Marine Research and Development Geo-EcoMarina Review, 11/2005

but also marine pollution monitoring (Fig. 2.3), the management of living resources, aquaculture, marine engineering and technology, and coastal lakes ecology [21], in the North-Western part of the Black Sea and the along Romanian coastline and in other areas of the World Ocean (Libya, Argentina, Somalia), as well. In time, the institute’s activity has diversified; scientific connections with prestigious international institutions were established, but also, with profile institutes belonging to the Black Sea coastal states [22]. Today, NIMRD has an important international activity with: – UNESCO/IOC/IODE—National Coordinator for Oceanographic Data Management – UNESCO/IOC/IODE—National Coordinator for Marine Information Management – UNESCO/IOC/GLOSS/MedGLOSS (Global Sea Level Observing System) – Black Sea GOOS – Working Group Member in IOC—“Global Ocean Science Report” (GOSR) NIMRD and the Romanian National Oceanographic and Environmental Data Center – NOEDC, part of the European and International Database and Operational Oceanography Systems (Fig. 2.4) [23]:

2.2 Black Sea Research in the Twentieth Century

39

Fig. 2.4 Modified excerpt from http://romania-seadatanet.maris2.nl/v_cdi_v3/browse_step.asp [24]

– EMODnet—European Marine Observation and Data Network (http://emodnet. eu/), assembles in a uniform and standardized system oceanographic data and related products – SeaDataNet—PAN-European Infrastructure for Ocean & Marine Data Management (www.seadatanet.org), distributes infrastructure for managing large and diverse data sets from satellite and in situ observation of the seas and oceans – Copernicus (http://marine.copernicus.eu/)—European Earth monitoring system/ marine monitoring service (http://marine.copernicus.eu/), provides regular and systematic reference information on the state of oceans and regional seas; the observations and forecasts are used in all marine applications – COSMOMAR—Constanța Space Technologies Competence Centre dedicated to the Romanian Marine and Coastal Regions Sustainable Development (www. cosmomar.ro), research infrastructure that facilitates cooperation and creates networks between local and regional stakeholders, and the synergistic exchange of data and information between the research projects, such as satellite and aerial teledetection In 1996, the International Ocean Institute founded the Black Sea Operational Centre, based on a memorandum concluded with the Black Sea University (founded by Academician M. Maliţa – Bucharest, 1993); beginning in 1999, the center performed activities at „Grigore Antipa” NIMRD (Fig. 2.5).

40

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The History of Research Conducted in the Black Sea

Kilia

Danube Sulina Tulcea Sulina Sfantu Gheorghe

Razim Lake

Romania

Sfantu Gheorghe

Gura Portitei

Midia Cape

Constanta Black Sea Tuzla Cape

Mangalia

Fig. 2.5 The Hydrological and meteorological stations on the Romanian Black Sea waters (according to “Grigore Antipa” NIMRD)

The primary objectives of this center’s activity can be synthesized as follows: oceanographical studies and the protection of the marine environment; courses and audit in the environment protection field; the interchange of scientific information and promoting of the general interest as regards the Black Sea area development; the stimulation of the national and international marine research development the development of a database regarding the environmental conditions in the Black Sea area [25]. The main activity of BSOC was the international seminar with the theme „Using Today’s Scientific Knowledge for the Black Sea Area’s Development Tomorrow” held at Constanța-Mamaia, in September 1999. The National Institute of Marine Geology and Geoecology Bucharest (GeoEcoMar) is a research and development institute, coordinated by the Ministry of Education and Research. This institute was constituted from the Laboratory of marine geology, a component of the Geology Institute from Bucharest, which began its activity in 1968. The scientific activity of the institute includes the geological

2.2 Black Sea Research in the Twentieth Century

41

study of the Danube-Delta-Black Sea geosystem, the climate and sea-level changes, as well as their impact on the environment and the economic-social development in the region. GeoEcoMar is a European and national excellency center for environment and geoecology studies for river-delta-sea systems, and its components are the laboratory of marine geology and sedimentology; the laboratory of seismology and sea physics; the laboratory of marine gravimetry and magnetometry; the department of data basis and GIS. The institute is a partner to critical international programs and also cooperates with critical scientific institutions from France, Germany, Italy, Switzerland, etc. The Maritime Hydrographic Directorate (MHD), founded in November 1955, is the successor of the Maritime Hydrographic Service (1926), which, between 1926 and 1944, performed the following activities: the hydrographical exploration of the Romanian maritime waters, the surveys at the Danube mouths to determine the coastal currents’ characteristics, the marine coastal current, studies regarding the delta’s advancement and also, tests made on Sacalin island, the coastal cordons research, the waters’ salinity measurement between the coastline and the marine current line, the reprinting of the seashore and depths map, among others. MHD was authorized to take over all the hydrographic matters, the signalization for navigation, and marine meteorology, inside the Romanian territorial waters. The campaigns of hydrographical explorations between 1959 and 1970 and 1973 and 1982, the publishing of the Pilot Book of the Black Sea (1981), and the conception and publishing of the entire set of national navigation maps in 2006 must be mentioned, too. Beginning in 1965, it represents Romania as a member state with full rights in the International Association of Lighthouse Authorities. After 1990, the institution has been reorganized, it moved into a new headquarters, and 24 new national navigation maps have been published. Starting in 2007, it represents Romania as a member state with full rights in the International Hydrographic Organization (Fig. 2.6). Last but not least, I considered it necessary to present the Romanian research vessels in the Black Sea, as well. The history of the vessels used in marine research began with „Olinka” sailing vessel [26] (with a wooden body, length 15 m, built-in 1866 at Tulcea), it continued with the “Delfinul” motorboat—1914 (length 9 m) and the “Concordia” vessel—1924 (length 21 m, displacement 325 t), renamed in 1948 as the “Delta,” “Emil Racoviţă" research vessel (length 15 m, used until 1966 for research of the Romanian coastline). Generally, fishing vessels of small dimensions and with a wooden body, as well as oceanic fishing vessels („Someşul”—3320 t, length 82 m; and the present research vessel „Mare Nigrum”—2690 t, length 88 m) have also been used. After 1990, the research vessel „Steaua de mare 1” participated in research programs CoMSBlack/NATO TU-Black Sea in 1994 (25 stations), 1995 (7 stations), and 1996 (17 stations). Furthermore, Romanian Military Navy ships were used for research in the Black Sea, such as Cruiser „Elisabeta” (length 73 m, displacement of 1320 t, speed

42

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The History of Research Conducted in the Black Sea

Fig. 2.6 Romania as a member state IHO Monaco, 2007. (Source: author’s photo)

18 knots, 181 officers and crew), „Mircea” brig (length 36 m, 360 t, draught 3.6 m, speed 10–11 knots); from its board the measurements for “Cătuneanu map” were performed, Gunboat “Griviţa,” used in the research of the marine currents studies (1927–1935), Gunboat “Lt.Cdor. Eugen Stihi,” a hydrographical vessel belonging to the Maritime Hydrographic Directorate, MV “Emil Racoviţă” (1850 t) and MV “Grigore Antipa” (3285 t) vessels belonging to the Diving Centre from Constanța. Under the auspices of the Natural Sciences Museum Complex from Constanta (having as components: the Aquarium, the Dolphinarium, the Exhibition named „Some of the riches and beauties of the World Ocean,” the Microreserve, the Exhibition of Exotic birds, and the Planetarium), a succession of scientific research regarding the Black Sea, such as aspects regarding the fish and dolphins’ adaptation in captivity, the scientists being focalized on their nutrition, and the physiological and behavioral reactions in case of some ecological factors variation (models have been elaborated as regards the physiology of their adaptation and the establishment of some principles and technologies to prevent the appearance of some ecophysiological imbalances), were approached. The rise and diversification of the Museum Complex heritage are one of the constant concerns, in this respect, specialists’ actions are remarkable during the observations programs, performed on the land, sea, as well as the collection of fish from different areas along the Romanian coastline. In conclusion, it can be demonstrated that the Black Sea represented (and still does) an ample and exciting research subject that attracts more and more scientists and institutions, mainly in the last decades, for long-term interdisciplinary research programs.

2.3 Black Sea Research in the Twenty-First Century

2.3 2.3.1

43

Black Sea Research in the Twenty-First Century Marine Research Institutions in the Black Sea Coastal States

Today in the Black Sea region, there are several marine research institutions [27]: 1. Romania: National Institute of Marine Geology and Geoecology (GeoEcoMar), Bucharest/Constanța; “Grigore Antipa” National Institute for Marine Research and Development (NIMRD), Constanţa, Romanian Maritime Hydrographic Directorate, Constanța 2. Bulgaria: Institute of Oceanology, Varna (Bulgarian Academy of Sciences); Institute of Fishing Resources, Varna 3. Turkey: the University of Istanbul; Institute of Marine Sciences and Management; Institute of Marine Sciences; Middle East Technical University, Erdemli; Dokuz Eylül University, Institute of Marine Sciences and Technology, Izmir; Karadeniz Technical University, Faculty of Marine Sciences, Trabzon; General Directorate of Mineral Research and Exploration, Istanbul; Department of Hydrography, Oceanography, and Navigation, Turkish Navy, Istanbul; Ministry of Agriculture and Rural Affairs, Central Fisheries Research Institute, Trabzon 4. Georgia: University of Georgia, Batumi; University of Tbilisi 5. The Russian Federation: “P.P.Shirshov” Institute of Oceanology (Southern Branch, Gelendzhik); Russian Academy of Sciences, Youzhmorgeologia – Gelendzhik, Soyuzmorgeologia (Southern Branch), Gelendzhik 6. Ukraine: “A.O. Kovalevsskiy” Institute of Biology of the Southern Seas, Sevastopol; Institute of the University of Odesa

2.3.2

Marine Research Vessels in the Black Sea

The main marine research vessels of the Black Sea coastal states are [27, 28]: Romania: 1. R/V Mare Nigrum, National Institute of Marine Geology and Geoecology (GeoEcoMar), built in 1971, rebuilt in 2002, length 82 m, draft 5 m, displacement 3200 tons (Fig. 2.7) 2. R/V Istros, National Institute of Marine Geology and Geoecology (GeoEcoMar), built in 1986, length 32 m, beam 6,90 m, draft 1,25 m, displacement 175 t (Fig. 2.8) 3. Laboratory/House Boat Halmyris, National Institute of Marine Geology and Geoecology (GeoEcoMar), length 32 m, beam 6,60 m, draft 0,60 m, displacement 90 t 4. R/V Steaua de Mare 1, National Institute for Marine Research and Development “Grigore Antipa,” length 25.80 m, draft 3,5 m; R/V Grigore Antipa,

44

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The History of Research Conducted in the Black Sea

Fig. 2.7 R/V Mare Nigrum. (Source: By courtesy of Prof. N. Panin, Marine Research Infrastructure in the Black Sea Region, 2012 [27])

Fig. 2.8 R/V Istros. (Source: by courtesy of Prof. N. Panin et al., The National Institute of Research and Development for Marine Geology and Geoecology–GeoEcoMar: twenty years of scientific activity, Geo-Eco-Marina, 18/2012 [27, 29, 30])

2.3 Black Sea Research in the Twenty-First Century

45

Fig. 2.9 R/V Commander Alexandru Catuneanu. (Source: by courtesy of Romanian Maritime Hydrographic Directorate [31])

Romanian Navy, built 1970, length 70.1 m, beam 10 m, draft 3.9 m, displacement 1930 tons 5. R/V Commander Alexandru Catuneanu, Maritime Hydrographic Directorate, built in 1995, length 64.8 m, beam 14.6 m, draft 5.5 m, displacement 2450 tons (Fig. 2.9)

Bulgaria: 1. R/V Akademik, Bulgarian Academy of Sciences, Institute of Oceanology, Varna, built in 1979, length 55.50 m, beam 9.8 m, displacement 1225 t, draft 4.8 m, crew 22, scientific staff 20 (Fig. 2.10) 2. R/V Professor A. Valkanov, Institute of Fishing Resources, Varna, length 34.00 m, built in 1979; Manned submersible PC-8, Bulgarian Academy of Sciences, Institute of Oceanology, weight 5500 kg, maximum operating depth 250 m, greatest beam 6.5 m (Fig. 2.11)

Turkey: 1. R/V Bilim-2, Institute of Marine Sciences, Erdemli, Middle East Technical University, built in 1983, length 40.36 m, tonnage 433 gross, 190 net tons, draft 3.80 m; R/V Erdemli, Institute of Marine Sciences Middle East Technical University, built in 1979, length 17 m, tonnage 30 gross tons; R/V K. Piri Reis; Dokuz Eylül University, Institute of Marine Sciences and Technology, Izmir, built in 1978, length 36 m; R/V Denar I, Karadeniz Technical University, Faculty of Marine Sciences, Trabzon, built in 1992, length 24.50 m; R/V

46

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The History of Research Conducted in the Black Sea

Fig. 2.10 R/V Akademik. (Source: by courtesy of .io-bas.bg [32])

Fig. 2.11 Manned submersible PC-8. (Source: By courtesy of Prof. N. Panin, Marine Research Infrastructure in the Black Sea Region, 2012 [27, 32])

2.3 Black Sea Research in the Twenty-First Century

47

Fig. 2.12 TCG Çesme. (Source: official picture from http://www.shodb.gov.tr/shodb_esas/index. php/en/general/about-us/survey-vessels)

Sismik 1, MTA General Directorate (General Directorate of Mineral Research and Exploration), Istanbul, built in 1942, rebuilt in 1976, length 55.75 m, draft 3.96 m, tonnage 750.44 gross, 275 net tons; R/V TCG Çubuklu, Turkish Navy, Department of Hydrography, Oceanography and Navigation, Istanbul, built in 1986, length/beam 40.47 m/9.58 m, draft 4.2 m, displacement 650 tons; R/V TCG Çesme, Turkish Navy, Department of Hydrography, Oceanography and Navigation Istanbul, year of building 1965, length/beam 87 m/14.6 m, draft 4.6 m, displacement 2900 tons; R/V Surat Arastirma 1, Ministry of Agriculture and Rural Affairs, Central Fisheries Research Institute, Trabzon, built in 1984, length 22.00 m; R/V Arar, University of Istanbul, Institute of Marine Sciences and Management, built in 1951, length 31.27 m, draft 3.20 m, tonnage 173.68 gross tons [34–40] (Fig. 2.12).

The Russian Federation: 1. R/V Professor Logachev, State Enterprise “Polar Marine Geosurvey Expedition,” Saint Petersburg, built in 1991, length 104.5 m, beam 16 m, draft 5.8 m, tonnage 4504 gross, 1351 net tons, displacement (empty/loaded) 3900/5620 tons; R/V Professor Stockman, Russian Academy of Sciences P.P.Shirshov Institute of Oceanology, built in 1979, length 68.77 m, draft 4.70 m, tonnage 1177 gross tons (Fig. 2.13) [41–43]

48

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The History of Research Conducted in the Black Sea

Fig. 2.13 R/V Professor Stockman. (Source: official picture from http://rv.ocean.ru/en/flot/abf/nisprofessor-shtokman.html)

Fig. 2.14 R/V Professor Vodyanitskiy. (Source: official picture from http://ocean.nodc.org.ua/ MHI_Scientists/photoavideo/53-rv-professor-vodyanitskiy-64.html)

Ukraine [44]: 1. R/V Professor Vodyanitskiy, National Academy of Sciences of Ukraine Institute of Biology of the Southern Seas, built in 1976, length 68.90 m (Fig. 2.14) [44]

2.3 Black Sea Research in the Twenty-First Century

2.3.3

49

International Organizations in the Black Sea Region

Some important international organizations operating in the Black Sea are listed below: 1. Black Sea Economic Cooperation (BSEC)—http://www.bsec-organization.org. [45], established in 1992 in Istanbul by the following countries: Albania, Armenia, Azerbaijan, Bulgaria, Georgia, Greece, The Republic of Moldova, Romania, The Russian Federation, Turkey and Ukraine; they signed the “The Summit Declaration on Black Sea Economic Cooperation” and “Bosporus Statement”; in June 1998, at Yalta, the “BSEC Charter” was signed, which entered into force on May 1, 1999 and became the fundamental document of the organization; in April 2003, the number of BSEC members increased to twelve by Serbia’s adherence; the organization created cooperation structures in the governmental, parliamentary, business, banking, academic and scientific fields; also multilateral cooperation agreements, respectively, Understanding and Assimilation Memorandums in the fields of fighting against organized criminality and terrorism were signed; the emergency assistance in case of disasters; the facilitation of road transportation for goods; the development of the Black Sea ring-shaped highway; the development of the Black Sea maritime highways; the cooperation between the diplomatic academies and institutes of the Member States. Romania signed and ratified all these documents; the organization covers an area of 2.2 million km2, with a population of over 350 million inhabitants, without an own regional identity; the region has strategic recognized importance, given by the rich natural resources, especially in the oil and gas fields, and an important potential market; in the region, the cumulative trade represents over 5% from the world trade. Romania is the coordinating country of the working groups related to fighting against criminality (2015–2017), transports (2015–2017), and environment protection (2016–2018). 2. In this sense, the Black Sea inclusion in the European Research System (EuroGOOS), as a part of the Global Oceanic Observation System (GOOS), must be mentioned [46]. GOOS was founded as a result of the marine researchobservation management needs at the planetary level, emphasized at the United Nations Conference for environment and development (UNCED), 1994. These materialized at the beginning of 2000 in two directions: the first, monitoring of the oceanic basins, the marine environment knowledge and climatic modifications; the second, research of the coastal areas (the impact on the human body and the marine ecosystems of the coastline modifications). EuroGOOS was founded in 1994, with the purpose of developing the GOOS programs in the European maritime areas, and is organized in five regions: Arctic, Baltic, Mediterranean, North Atlantic, and the shelf from north-west Europe. GOOS Black Sea (of which Romania is a party, too) has developed as follows (http:// www.ims.metu.edu.tr/Black_Sea_GOOS/):

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– 1994, the workshop regarding the regional cooperation for the marine research-Varna; one of the consequences of this meeting being the two pilot projects (one for the GOOS Black Sea constitution and the other one as regards the flows in the Black Sea) – 1997, the first workshop regarding the flows in the Black Sea-Istanbul – 1997, the Black Sea-Varna International Conference – 1997, the Black Sea Universities Network (BSUN), founded to develop educational, scientific, and cultural cooperation and exchanges among the Universities of the BSEC Member States and other institutions with similar concerns, http://www.bsun.org – 1999, the first workshop of GOOS Black Sea-Varna – 2001, the second workshop of GOOS Black Sea-Poti 3. In 1991, the Cooperative Marine Science Programme for the Black Sea (CoMSBlack), financed by the Intergovernmental Oceanographic Commission (IOC) of UNESCO, attended by Bulgaria, Georgia, Romania, Russia, Turkey, Ukraine, and the United States. 4. In 1992, the Commission on the Protection of the Black Sea against Pollution (Black Sea Commission, BSC), http://www.blacksea-commission.org/. 5. In 1998, the International Centre for Black Sea Studies (ICBSS), a nonprofit organization, independent research, and training institution focusing on the wider Black Sea region, is a related body of Organisation of the Black Sea Economic Cooperation (BSEC) and serves as its acknowledged think-tank, http://icbss.org/. 6. In 1998, the Black Sea NGO Network (BSNN), registered in 1999, a regional association of NGOs from all Black Sea countries, http://www.bsnn.org/. 7. The Black Sea Trust for Regional Cooperation (BST) promotes regional cooperation and good governance in the wider Black Sea region, http://www.gmfus. org/blacksea 8. 2002–2010, Centre for Black Sea Studies, with a generous grant from the Danish National Research Foundation and with significant cofunding from the University of Aarhus, especially the Faculty of Humanities, http://www.pontos. dk/ 9. In 2002, the Black Sea Biodiversity and Landscape Conservation Protocol, http://www.blacksea-commission.org/_convention-protocols-biodiversity.asp 10. In 2004, the Baku Initiative, a policy dialogue on energy cooperation between the European Union and the coastal states of the Black Sea, Caspian Sea, and their neighbors, undertaken as part of the INOGATE program, http://ec.europa. eu/dgs/energy_transport/international/regional/caspian/energy_en.htm 11. 11.2010–2014, EU FP7 SEAS-ERA project, a European Network of Marine Research Funding Organizations located along the Atlantic, Mediterranean, and Black Seas and the European seaboard, http://www.seas-era.eu 12. In 2007, the Black Sea Synergy program was developed by the EU to tackle concrete initiatives looking at areas like transport, energy, the environment, maritime management, fisheries, migration, and the fight against organized

2.3 Black Sea Research in the Twenty-First Century

13.

14. 15.

16.

51

crime, the information society, and cultural cooperation, http://eeas.europa.eu/ blacksea/index_en.htm In 2007, the Black Sea Trust for Regional Cooperation (BST, a grantmaking initiative based in Bucharest, Romania, created by The German Marshall Fund of the United States, with the support of the United States Agency for International Development (USAID), Charles Stewart Mott Foundation, the Ministry of Foreign Affairs of Romania, the Government of Latvia, and the Lynde and Harry Bradley Foundation, the Robert Bosch Stiftung and Calouste Gulbenkian Foundation and the European Commission In 2008, Regional group on Research Infrastructures ESFRI, http://ec.europa.eu/ research/infra-structures/ In 2009, the Commission on the Black Sea was formed to suggest ways for this increasingly important but volatile region to move in the direction of cooperation and collaboration, http://www.blackseacom.eu In 2011, the Danube Strategy Initiative, http://ec.europa.eu/regional policy/ cooperate/danube/

2.3.4

International Programs/Projects in the Black Sea Region in the Twenty-First Century

Several important international scientific research programs in recent years in the Black Sea basin included the following: • 2003–2006, A Regional Capacity Building and Networking Programme to Upgrade Monitoring and Forecasting Activity in the Black Sea Basin (ARENA), the first project in the Black Sea bringing together the regional oceanographic institutes, hydrometeorological and international organizations from Black sea Region, and Europe; https://cordis.europa.eu/project/id/EVK3-CT-2002-80011. • 2004, Interstate Oil and Gas Transport to Europe Programme (INOGATE), an international energy cooperation program between the European Union, the coastal states of the Black and Caspian Seas and their neighboring countries, http://www.inogate.org/inogate_programme/. • 2005–2006, International Action for Sustainability of the Mediterranean and the Black Sea Environment (IASON); the project outlines collaboration and clustering schemes involving environmental, economic, and scientific organizations in the Mediterranean, the Black Sea, and other EU nations to create synergies in networking and exchanges at several levels, addressing the system of interconnected basins as one, eem.it/en/research/programs/climate-change-economic-impacts-and-adaptation/past-projects/international-action-for-sustainability-of-the-mediterranean-and-black-sea-environment-iason/. • 2005–2008, A supporting program for capacity building in the black sea region towards the operational status of oceanographic services (ASCABOS); the project aims to increase public awareness and to stimulate and motivate the

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• •

•

• •

• • •

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The History of Research Conducted in the Black Sea

utilization of operational oceanographic information in management and decision-making practices, https://cordis.europa.eu/project/id/518063/it. 2005–2008, The Black Sea Scene, a Black Sea Scientific Network of leading environmental and socio-economic research institutes, universities and NGOs from the countries around the Black Sea, http://www.blackseascene.net [47]. UPGRADE BlackSeaScene from 2008 to 2011; this project is undertaken by 51 partners, of which 43 are located in the Black Sea countries; the metadata services are aimed to make out Black Sea scientific information and data easier traceable by scientists and the general public and can be divided into: EDMED— Marine and Environmental Dataset catalogue, Data Quality Control (DQC) methods overview, and reference to support tools; EDMERP—Marine and Environmental Project catalogue; EDMO—Directory of Marine Organizations active in Black Sea region; CSR—Directory of Marine Research Cruises in the Black Sea; marine biology—metadata directories of important marine species; scientists—directory of marine specialists active in Black Sea region; bibliography— scientific reports and publications on the Black Sea, socio-economic data on the Black Sea, Black Sea data products—an overview of specific data products developed under SeaDataNet by Black Sea partners; Black Sea EDIOS (ASCABOS project)—an overview of the current operational oceanography in the Black Sea by the bordering countries. 2006–2008, Plan Coast Project an INTERREG IIIB NP CADSES for effective integrated planning in coastal zones and maritime areas in the Baltic, Adriatic, and Black Sea regions, http://www.plancoast.eu. 2007–2013, From the Aegean to the Black Sea – medieval Ports in the Maritime Routes of the East – OLKAS, co-funded by the European program «“Joint Operational Program BLACK SEA 2007–2013”» and by national resources, and it is coordinated by the European Centre of Byzantine and Post Byzantine Monuments (E.K.B.M.M.) [48]. 2009–2011, The UP-GRADE BS-SCENE Project, EU funded project, for extending the existing research infrastructure with additional 19 marine environmental institutes/organizations from the 6 Black Sea countries, http://www. blackseascene.net [48]. 2008–2012, IncoNet EECA Project, a partnership between the countries of the European Union and Eastern Europe/Central Asia, for the political, economic, and social development of both regions, http://www.inco-eeca.net/. 2009–2012, Support Action to initiate Cooperation between the Communities of European MARine and MARitime REsearch and Science (EMAR2RES), a forum for interaction between Europe’s marine and maritime research communities, http://www.waterborne-tp.org/. 2009–2012, ERA.NET RUS Project, intensifying and strengthening S&T cooperation between Russia and Europe, http://www.eranet-rus.eu/. 2006–2011, The Black Sea SCENE project, an FP 6 and FP 7 EU-funded project, http://www.blackseascene.net. 2009–2012, BS ERA-NET Project, a networking project to integrate the participating countries from the Black Sea extended region in the European Research Area – http://www.seas-era.eu.

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• 2010–2014, The EU SEAS-ERA project—a European Network of Marine Research Area (ERA) http://www.seas-era.eu/np4/homepage.html [49]. • 2011–2013, Integration of European marine research networks of excellence (EUROMARINE), a durable integration between the major European marine networks—EUR-OCEANS, MarBEF, and Marine Genomics Europe – http:// www.euromarineconsortium.eu/. • 2011–2014, Technologies II, MARTEC II Project, http://www.martec-era.net/. • 2011–2013, Interpretative Trails on the Ground: Support to the Management of Natural Protected Areas in the Black Sea Region, InterTrails Project, activities and management and conservation of protected territories on a regional scale, http://www.trails.bsnn.org/ [50]. • 2012–2015, Policy-orientated marine Environmental Research for the Southern European Seas (PERSEUS), the dual impact of human activity and natural pressures on the Mediterranean and Black Seas, http://www.perseus-net.eu/. • 2010–2013, Implementation of an integrated early warning system for the adequate detection, assessment, forecasting, and rapid notification of natural marine geohazards of risk to the Ro-Bg Black Sea cross-border area MARINEGEOH AZARD, http://www.geohazard-blacksea.eu/ [51]. • 2013–2015, Submarine Archaeological Heritage of the Western Black Sea Shelf HERAS, http://www.herasprojectcbc.eu/ [52]. • 2012–2014, Black Sea Joint Regional Research Centre for Mitigation and Adaptation to the Global Changes Impact MAREAS, http://www.mareas-info.eu • 2012–2015, Policy-oriented marine Environmental Research for the Southern European Seas PERSEUS, http://www.perseus-net.eu/site/. • 2012–2016, CoCoNet Towards Coast to Coast NETworks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential, http://www.coconet-fp7.eu/. • 2011–2013, Industrial Symbiosis Network for Environment Protection and Sustainable Development in Black Sea Basin (SymNet, http://blacksea-cbc.net/wpcontent/uploads/2015/12/20120524-Priority-1-Symnet-92.pdf. • 2012–2014, From Aegean to the Black Sea. Medieval Ports in the Maritime Routes of the East OLKAS, http://blacksea-cbc.net/wp-content/uploads/201 5/12/20120620-Priority-1-Olkas-168.pdf. • 2011–2013, Black Sea Network of Regional Development (BlasNET), http:// blacksea-cbc.net/wp-content/uploads/2015/12/20120719-Priority-1BlasNET-96.pdf. • 2011–2013, Facilitate the trade of agro-food products in the Black Sea Basin (FTAP), http://blacksea–cbc.net/wp-content/uploads/2015/12/20120723-Prior ity-1-FTAP-77.pdf. • 2011–2012, Black Sea Tradenet (BST), http://blacksea-cbc.net/wp-content/ uploads/2015/12/20120723-Priority-1-BST-113.pdf. • 2012–2013, Black Sea – Solidarity and Economic Activity – BS – SEA, http:// blacksea-cbc.net/wp-content/uploads/2015/12/20120803-Priority-1-BS-SEA-98. pdf.

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• 2011–2013, Capacity for Integrated Urban Development, INTEGRABLE, http:// blacksea-cbc.net/wp-content/uploads/2015/12/20120821-Priority-1-INTEGRA BLE-99.pdf. • 2011–2013, Tradition, Originality, Uniqueness, and Richness for an Innovative Strategy for Tourism Development in Black Sea Region (TOURIST), http:// blacksea-cbc.net/wp-content/uploads/2015/12/20120903-Priority-1-TOUR IST-137.pdf. • 2011–2013, Interpretative Trails on the Ground – Support to the Management of Natural Protected Areas in the Black Sea Region (Inter Trails), http://blackseacbc.net/wp-content/uploads/2015/12/20120524-Priority-2-Inter-Trails-150.pdf. • 2011–2013, Strengthening the regional capacity to support the sustainable management of the Black Sea Fisheries ( SRCSSMBSF ), http://blacksea-cbc. net/wp-content/uploads/2015/12/20120614-Priority-2-SRC SSMBSF-88.pdf. • 2012–2014, Black Sea Earthquake Safety Net (work) (ESNET), http://blackseacbc.net/wp-content/uploads/2015/12/20120806-Priority-2-ESNET-80.pdf. • 2011–2013, Development of a common intraregional monitoring system for the environmental protection and preservation of the Black Sea (ECO-SATELLITE), http://blacksea-cbc.net/wp-content/uploads/2015/12/20120803-Priority-2-ECOSATELLITE-36.pdf. • 2012–2013, Raising Public Awareness on Solid Municipal Waste Management in the North West of the Black Sea Region (Less Waste in the North West), http:// blacksea-cbc.net/wp-content/uploads/2015/12/20120809-Priority-2-Less-Waste -in-the-North-West-83.pdf. • 2012–2014, Research and Restoration of the Essential Filters of the Sea – REEFS, http://blacksea-cbc.net/wp-content/uploads/2015/12/20120828-Priority2-REEFS-86.pdf. • 2011–2013, Black Sea Cultural Animation Programme Pilot model for mobilizing the common cultural characteristics for creative destination management in the Black Sea Basin, http://blacksea-cbc.net/wp-content/uploads/2015/12/20120 524-Priority-3-Cultural-Animation Program-26.pdf. • 2011–2013, BSUN Joint Master Degree Study Program on the Management of Renewable Energy Sources (ARGOS), http://blacksea-cbc.net/wp-content/ uploads/2015/12/20120711-Priority-3-Argos-127.pdf. • 2012–2014, Industrial Evolution in the Black Sea Area—Examples from Greece, Romania, and Armenia (IEBSA), http://blacksea-cbc.net/wp-content/ uploads/2012 0120823-Priority-3-IEBSA-131 .pdf5/12/. • 2011–2012, Dialogue Between Cultures, http://blacksea-cbc.net/wp-content/up loads/2015/12/20120903-Priority-3-Dialogue-between-Cultures-71.pdf. • 2012–2015, History of the Black Sea, 18th–20th century, https://project.blacksea.gr/. • 2015–2018, The Black Sea Maritime Archaeology Project (Black Sea MAP), a three-year interdisciplinary expedition researching ancient coastlines and seafaring history of the Bulgarian Black Sea, http://blackseamap.com/ [53]. • 2015–2017, Cross-Border Maritime Spatial Plan for the Black Sea MARSPLAN BS-Romania, Bulgaria, https://ec.europa.eu/easme/en/cross-border-maritime-spa tial-planblack-sea-romaniabulgaria [54];

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• 2017–2018, Integrated Bulgarian Maritime Surveillance, https://ec.europa.eu/ easme/en/integrated-bulgarian-maritime-surveillance. • Implementation of a geophysical investigation and monitoring tool of the Romanian maritime space security - MAR S, experimental-demonstrative implementation of a set of geophysical methods of investigation and monitoring of the submarine domain, together with the organization of the existing and acquired information in a GIS database. • 2019, Expert Group of the Blue Growth Initiative for Research and Innovation in the Black Sea, Black Sea Strategic Research and Innovation Agenda, to promote blue growth and economic prosperity of the Black Sea region and build critical support systems and innovative research infrastructure and to improve education and capacity building, http://www.sust-black.ro/Black%20Sea%20Strategic%20 Research%20and%20Innovation%20Agenda.pdf [55]. • 2018–2020, Assessing the vulnerability of the Black Sea marine ecosystem to human pressures (ANEMONE), Joint Operational Programme Black Sea Basin 2014–2020, carried out by the NIMRD Romania in partnership with the TÜDAV, the Scientific and Technological Research Council of Turkey/Marmara Research Center (TÜBİTAK-MAM), the Institute of Oceanology/Bulgarian Academy of Sciences, the Ukrainian Scientific Center of Ecology of the Sea (UkrSCES) and the nongovernmental organization Mare Nostrum, Romania (Fig. 2.15), https:// blacksea-cbc.net/projects-newsevents/anemone-bsb319-tools-and-indicators-forthe-integrated-assessment-of-black-sea-environmental-status/ [56, 57].

Fig. 2.15 Anemone Joint Cruise, 2019. (Adapted from ANEMONE Project, http:// anemoneproject.euusingafreesupportmapofGiorgiBalakhadze. https://upload.wikimedia.org/ wikipedia/commons/d/da/Map_of_the_Black_Sea_with_bathymetry_and_surrounding_relief.svg)

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• 2014–2020, ENI CBC Black Sea Basin Joint Operational Programme, https:// blacksea-cbc.net/black-sea-basin-2014-2020/ [58]. • 2002–2017, Argo measurements in the Black Sea started with the operations of 7 [T/S] (temperature/salinity) floats deployed in 2002–2006 as part of collaboration between the Institute of Marine Sciences of the Middle Eastern Technical University (METU-IMS, Turkey) and the University of Washington (USA). Then Germany deployed 2 [T/S + DO (Dissolved Oxygen)] floats in 2009 and France deployed 2 [T/S] floats in 2009–2010. Bulgaria, boosted by the Euro-Argo Preparatory Phase project, deployed 4 floats in 2011–2013. Since 2002, a total of 37 floats have been deployed in the Black Sea, 11 units were still active at the end of January 2017. All floats have cycles of 5 days and parking depths between 200 and 1000 m. Most floats have alternated maximal profiling depths of 700 and 1500 m. Except for the two German floats, all floats have been deployed by teams from the Institute of Oceanology, Bulgarian Academy of Science (IOBAS, Bulgaria), METU (Turkey) and GeoEcoMar (Romania). In December 2016, an Argo float was deployed in the south-western Black Sea during a DEKOSIM cruise aiming at elucidating water mass transport from the north-western shelf and its nutrient dynamics along the southern Black Sea coast as well as biochemical measurements along with the oxic-anoxic interface (Fig. 2.16) [59, 60, 61]. • MOCCA project (Monitoring the Oceans and Climate Change with Argo) started end of June 2015 and is scheduled for a 5-year period (2015–2020) (Fig. 2.17) [62]. • 2018–2021, CMEMS BS Copernicus Back Sea Monitoring Forecasting Centre – Phase 2. This contract is issued within the EU Copernicus Marine Environment

Odesa

Azov Sea Black Sea shelf Novorosiysk Constanta

Black Sea Varna

Batumi

Marmara Sea

Instanbul

Fig. 2.16 Black Sea Argo Floats, 2017. (Modified from public picture from https://www.euroargo.eu/News-Meetings/News/News-archives/2017/Argo-activities-in-the-Black-Sea)

2.3 Black Sea Research in the Twenty-First Century

Ukraine

Odesa

57

Azov Sea Russian Federaon

Black Sea shelf Romania Novorosiysk

Constanta

Bulgaria Black Sea

Varna

Georgia

Batumi

ul bu b nbu n an aanb anbu ssttanb Inst Instanbul Inst Istanbul

Marmara Sea

Turkey

Fig. 2.17 MOCCA floats last positions in the Black Sea, August 4, 2020. (Modified from public picture, https://www.euro-argo.eu/EU-Projects/MOCCA-2015-2020/Access-to-MOCCA-Data)

Monitoring Service (CMEMS) to provide regular information about the physical state of the ocean and marine ecosystems for the Black Sea. Continuous production of data about the Black Sea including analysis, 10 days forecasts, and reanalysis, describing waves, currents, temperature, salinity, sea level, and biogeochemistry, https://www.cmcc.it/projects/cmems-bs-mfc-copernicus-blacksea-monitoring-forecasting-centre-phase-2 [63]. Nowadays, available in situ, almost all data from the Black Sea (Fig. 2.18) are provided by Copernicus marine environment monitoring service (CMEMS) INS-TAC [64]. The first two Black Sea GOOS EU projects FP5 ARENA and FP6 ASCABOS fulfilled their mission set out in the Black Sea GOOS Strategic Action and Implementation Plan and had fostered the development of operational oceanography in the region [63]. Black Sea MSP Projects Maritime Spatial Planning (MSP) is defined in the EU Directive on MSP as a process by which the relevant Member State’s authorities analyze and organize human activities in marine areas to achieve ecological, economic, and social objectives, according to the European Commission’s Directive on Maritime Spatial Planning. MSP is seen as an integrative process to cope with the increasing demand for maritime space from traditional and emerging sectors while preserving the proper functioning of the marine ecosystems [65, 66]: 2006–2008, PlanCoast, Tools and capacities for effective integrated planning in coastal zones and maritime areas in the Baltic, Adriatic, and the Black Sea regions, https://www.msp-platform.eu/projects/tools-and-capacities-effectiveintegrated-planning-coastal-zones-and-maritime-areas.

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Ukraine Odesa

Azov Sea

Russian Federaon

Novorosiysk

Romania Constanta

Black Sea

Bulgaria Varna

Georgia Batumi Istanbul

Marmara Sea

Turkey

Fig. 2.18 Black Sea in situ data. (Source: by courtesy of Prof. A. Palazov, Black Sea Observing System, https://www.frontiersin.org/articles/10.3389/fmars.2019.00315/full) [64]

2010–2014, PEGASO, People for Ecosystem-Based Governance in Assessing Sustainable Development of Ocean and coast, https://www.msp-platform.eu/ projects/people-ecosystem-based-governance-assessing-sustainable-develop ment-ocean-and-coast. 2011–2013, SymNet/CBC-Black Sea, Industrial Symbiosis Network for Environment Protection and Sustainable Development in Black Sea Basin, https://www. msp-platform.eu/projects/industrial-symbiosis-network-environment-protectionand-sustainable-development-black. 2013–2014, ICZM/CBC-Black Sea, Improvement of Coastal Zone Management in the Black Sea Region, https://www.msp-platform.eu/projects/improvementcoastal-zone-management-black-sea-region. 2011–2013, SRCSSMBSF, Strengthening the Regional Capacity to Support the Sustainable Management of the Black Sea Fisheries, https://www.mspplatform.eu/projects/strengthening-regional-capacity-support-sustainable-man agement-black-sea-fisheries. 2011–2014, CREAM, Coordinating Research in Support to Application of Ecosystem Approach to Fisheries and Management Advice in the Mediterranean and

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Black Seas, https://www.msp-platform.eu/projects/coordinating-research-sup port-application-ecosystem-approach-fisheries-and-management. 2016–2017, MARSEA, Development of an integrated framework for marine spatial planning in Romania, https://www.msp-platform.eu/projects/marsea-develop ment-integrated-framework-marine-spatial-planning-romania. 2016, COCONET, towards COast to COast NETworks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential (CoCoNET), https://www.msp-platform.eu/projects/coconet-towardscoast-coast-networks-marine-protected-areas-shore-high-and-deep-sea. 2015–2018, MARSPLAN-BS, Cross-Border MARitime Spatial PLANning in the Black Sea, https://www.msp-platform.eu/projects/cross-border-maritime-spatialplanning-black-sea. 2016–2018, ECOAST (COFASP), new methodologies for an ecosystem approach to spatial and temporal management of fisheries and aquaculture in coastal areas, https://www.msp-platform.eu/projects/ecoast-new-methodologies-ecosystemapproach-spatial-and-temporal-management-fisheries. 2019, Strategic Research and Innovation Agenda (SRIA) for the Black Sea coastal countries the Republic of Bulgaria, Georgia, Romania, the Russian Federation, the Republic of Turkey, Ukraine, and the Republic of Moldova, in cooperation with marine experts from leading European marine institutes and organizations, and with the support of the European Commission, have developed the Black Sea Strategic Research and Innovation Agenda with the aim of advancing a shared vision for a productive, healthy, resilient, sustainable and better valued the Black Sea by 2030 [67]. As a first step, the Strategic Research and Innovation Agenda will guide researchers, academia, funding agencies, industry, and policymakers to promote the social well-being, prosperity of Black Sea citizens and support economic growth and jobs of countries bordering it [65]. Selected projects supporting the Black Sea SRIA are: – COCONET (Towards COast to COast NETworks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential—EU Framework Programme for Research and Development (FP7) – DANUBIUS-RI: The International Centre for Advanced Studies on River Sea Systems—EU Framework Programme for Research and Development (HORI ZON 2020) – DEKOSIM: National Excellence Centre in Marine Ecosystem and Climate Research – EMBLAS-PLUS: Improving Environmental Monitoring in the Black Sea– Selected Measures—EU/UNDP – ERANet SEAS-ERA: Towards Integrated Marine Research Strategy and Programmes—EU Framework Programme for Research and Development (FP7) ERA-NET – MASRI (Infrastructure for sustainable development of marine research linked to the membership of Bulgaria in Euro-Argo EU infrastructure) – PEGASO: People for Ecosystem-based Governance in Assessing Sustainable development of Ocean and coast—EU Framework Programme for Research and Development (FP7)

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– PERSEUS (Policy-oriented marine Environmental Research in the Southern European Seas)—EU Framework Programme for Research and Development (FP7) – 2020–2022, “Black Sea Archaeology, History and Culture Portal – ARHICUP” Project, funded by the program “Joint Operational Programme Black Sea Basin 2014–2020,” https://arhicup.com/arhicup-project/ [68]

2.4

Conclusions

From early antiquity, the Black Sea coast’s natives, Phoenicians, Greeks, and later, Romans, Byzantines, Ottomans, Vikings, Venetians, Genoese sailors, and others undertook expeditions along the coasts and of the Black Sea for exploration and commercial and military purposes. The systematic exploration of the Black Sea area begins in the nineteenth century and continued in force in the twentieth and twenty-first centuries. Today, in the Black Sea, there are many international and national institutions whose main responsibilities are scientific research on geology, mineral, energy, and living resources, as well as their exploitation possibilities, navigation, seaborne trade, economy, politics, and geopolitics, ecology, archeology, and so on. For these, considerable financial, material, and human resources are allocated and national and international scientific and economic research programs have been and are being carried out, in which numerous research vessels and an increasing number of researchers participate annually. It can be said that the interest in Black Sea research is special and growing, both for the coastal states and for the international scientific, political, and economic environment. In this sense, a regional cooperation system (Romania-Bulgaria) was established on the Black Sea’s western coast the Black Sea Security System formed of: 1. EUXINUS—First regional early warning system for marine geohazard of risk to Romanian-Bulgarian Black Sea coastal area, realized through CBC Romania-Bulgaria 2007 structural funds, with two operational Centers to GeoEcoMar Constanţa Branch and IO-Bas Varna: the centers operate the EUXINUS network, an integrated multiparameter system, composed of five marine and coastal gauges, having the main objectives to provide data for tsunamis generation and propagation in the western Black Sea basin, log time series of physical and biochemical data regarding the properties of the water masses, and local meteorogical parameters. 2. GeoPontica—A coastal network to geodynamic surveillance with 18 DGPS stations, 13 in Romania and five in Bulgaria. The network is composed of water level sensors, Radar tide gauge sensor, pressure sensors, tide gauge data loggers, communication systems, seismometers, and accelerometers. The EUXINUS Centers send notifications in case of risk for Romanian and Bulgarians coastal area to Inspectorate for Emergency Situations.

References

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References 1. Brătianu G (1986) Black Sea. Meridiane Publishing House Bucharest, (in Romanian) 2. Kos’yan RD, Magoon OT (1993) Man of the Black Sea. In: Kos’yan R (ed) Coastlines of the Black Sea. American Society of Civil Engineers, New York 3. Panin N et al (1971) Bathymetric researches on the Black Sea continental platform, Research and studies of geology, geophysics, geography. The Geophysics 15 4. Trufaş VSRR (1970) Hydrology, Ist Part, Black Sea, University from Bucharest 5. ***The Black Sea in the Romanian coast area, Hydrological Monography, Bucharest, 1973. 6. Belberov Z, Konsulov A (1991) Bulgarian Research in the Black Sea. International workshop on the Black Sea focus on the Western Black Sea Shelf, Varna 7. Kubryakov AI et al (2012) Black Sea coastal forecasting system. Ocean Sci 8:183–196, www. ocean-sci.net/8/183/2012/ 8. Ünlüata Ü, Izdar E (1991) Black Sea Country profile for Turkey. International workshop on the Black Sea focus on the Western Black Sea Shelf, Varna 9. Frangopol PT (2000) The Black Sea relevance in the next millennium’s sustainable development, today’s scientific knowledge for tomorrow Black Sea Area’s development. IOI/BSOC, Constanta 10. Murray JW, Kempe S (1991) Previous research in the Black Sea by scientists from Western Europe and the United States. International Workshop on the Black Sea Focus on the Western Black Sea Shelf, Varna 11. Eremeev VN (1991) Contemporary State of the hydrophysical investigations of the Black Sea. International workshop on the Black Sea focus on the Western Black Sea Shelf, Varna 12. Bologa AS (1998) Regional Research and Management Development in the Black Sea, Cercetări marine – Recherches marines, no. 31. I.R.C.M, Constanta 13. Hombach VH (2007) The Black Sea Flood question, changes in coastline, climate and human settlement. Springer, Dordrecht 14. Enăchescu C (1973) D.H.M. contribution for the hydrographical and oceanographical study of the Romanian maritime area, Cercetări marine – Recherches marines 9. I.R.C.M, Constanta 15. Bologa AS, Marinescu A (2002) Romanian developmental contribution of Emil Racovitza and Grigore Antipa to the scientific exploration of the Mediterranean. In: Benson R, Rehback PF (eds) Oceanographic history. The Pacific and Beyond. University of Washington Press, Seattle/London, pp 275–279 16. Şerpoianu G, Malciu V (2002) The pioneers of Oceanographic research in Romania. Keith R, Benson, Rehback PF (eds), Oceanographic History University of Washington Press, Seattle/London, p 271 17. Ciocârdel R (1938) La circulation générale des eaux de la Mer Noire. Socec & Co., Bucuresti 18. Bologa AS (1989) Development of Marine Benthic Algology in Romania, Noesis 15, Bucharest 19. Bologa AS et al (1993) Romanian involvement in Black Sea Research, Black Sea Research Country profile. Inter-governmental Oceanographic Commision, UNESCO, Paris 20. Iordănescu V (1972) The Romanian Marine Research Institute. Cercetări marine – Recherches marines 1 I.R.C.M. Constanta 21. Bologa AS (2000) The Romanian Marine Research Institute at its 20th anniversary: tradition, status, perspectives. Cercetări marine – Recherches marines 23, I.R.C.M. Constanta 22. Bologa AS (1992) International relations of the Romanian Marine Research Institute at its 20th Anniversary: Necessity, Achievements, Prospects. Cercetări marine – Recherches Marines 24–25/1991/1992, I.R.C.M. Constanta 23. Buga L, Nicolaev S (2017) Oceanography, coastal and marine engineering. Workshop: Romanian hydrography – past and future, Romanian Maritime Hydrographic Directorate, Constanta 24. ***http://romania-seadatanet.maris2.nl/v_cdi_v3/browse_step.asp, 2017 25. Bologa AS (2000) The IOI- Black Sea Operational Centre, Using Today’s Scientific Knowledge for Tomorrow Black Sea Area’s Development, IOI/BSOC, Constanta 26. Bologa AS, Papadopol NC, Nae I (1999) Evolution des moyens nautiques de recherche océanologique en Roumanie (1843–1996), Travaux de Comité Roumain d’Histoire et de la Philosophie de Sciences, XXIV, Romanian Academy, Bucharest

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2

The History of Research Conducted in the Black Sea

27. Panin N (2012) Marine Research Infrastructure in the Black Sea Region 28. Panin N et al (2012) The National Institute of Research and Development for Marine Geology and Geoecology – GeoEcoMar: twenty years of scientific activity, Geo-Eco-Marina 18/2012 29. ***https://www.geoecomar.ro/website/en/ 30. ***http://www.rmri.ro/Home/Home.html?lang¼en 31. ***https://www.dhmfn.ro/index_en.html 32. ***http://www.io-bas.bg/index_en.html 33. ***http://www.ciesm.org/online/institutes/inst/Inst31.htm 34. ***https://www.istanbul.edu.tr/enstituler/denizbilimleri/denizbilimleri.htm 35. ***https://ims.metu.edu.tr/ 36. ***http://imst.deu.edu.tr/en/ 37. ***http://www.ktu.edu.tr/fishtecheng 38. ***http://www.shodb.gov.tr/shodb_esas/index.php/en/ 39. ***https://arastirma.tarimorman.gov.tr/sumae/Sayfalar/EN/AnaSayfa.aspx 40. ***https://www.bsu.edu.ge/?lang¼en 41. ***https://www.tsu.ge/en/ 42. ***https://ocean.ru/en/index.php?option¼com_k2&view¼item&id¼59:the-sou-thern-branchof-the-p-p-shirshov-institute-of-oceanology&Itemid¼161 43. ***http://www.ciesm.org/online/institutes/inst/Inst138.htm 44. ***https://www.ihu.com.ua/ 45. ***http://www.bsec-organization.org/ 46. ***http://www.ims.metu.edu.tr/Black_Sea_GOOS/ 47. ***http://www.blackseascene.net 48. ***http://www.olkas.net/com/7_The-project 49. ***http://www.seas-era.eu/np4/homepage.html 50. ***http://www.trails.bsnn.org 51. ***http://www.geohazard-blacksea.eu/ 52. ***http://www.herasprojectcbc.eu 53. ***http://blackseamap.com/ 54. ***https://ec.europa.eu/easme/en/cross-border-maritime-spatial-plan-black-searomaniabulgaria 55. ***http://www.sustblack.ro/Black%20Sea%20Strategic%20Research%20and%20Innovation %20Agenda.pdf 56. ***https://blacksea-cbc.net/projects-newsevents/anemone-bsb319-tools-and-indicators-forthe-integrated-assessment-of-black-sea-environmental-status/ 57. ***http://anemoneproject.eu 58. ***https://www.cmcc.it/projects/cmems-bs-mfc-copernicus-black-sea-monitoring-forecastingcentre-phase-2 59. ***https://ec.europa.eu/info/news/launch-european-black-sea-strategic-research-and-innova tion-agenda-2019-may-08_en, 2019 60. ***https://blacksea-cbc.net/black-sea-basin-2014-2020/ 61. Balan S et al, Argo activities in the Black Sea, https://www.euro-argo.eu/News-Meetings/News/ News-archives/2017/Argo-activities-in-the-Black-Sea 62. ***https://www.euro-argo.eu/EU-Projects/MOCCA-2015-2020/Access-to-MOCCA-Data 63. ***https://www.cmcc.it/projects/cmems-bs-mfc-copernicus-black-sea-monitoring -forecast ing-centre-phase-2 64. Palazov A et al, Black Sea observing system, https://www.frontiersin.org/articles/10.3389/ fmars.2019.00315/full 65. ***https://www.msp-platform.eu/msp-eu/introduction-msp 66. ***https://www.msp-platform.eu/practices/misis-black-sea-marine-atlas 67. ***https://ec.europa.eu/info/news/launch-european-black-sea-strategic-research-and-innova tion-agenda-2019-may-08_en 68. ***https://arhicup.com/arhicup-project/

Chapter 3

The Morphohydrography and Morphodynamics of the Black Sea

Abstract The Black Sea’s hydrographic network, coastline depths, and seafloor relief are topics of utmost importance in the study of its today morphohydrography and morphodynamics. The hydrographic network of the Black Sea basin stretches on a large surface of Eurasia, 22 countries, of over 22 million km2. Keywords Black Sea · Coastlines · Relief · Sea bottom The main elements of morphohydrography and morphodynamics of the Black Sea refer to the hydrographic network, coastline, depths, relief, and nature of the sea bottom.

3.1

The Hydrographic Network of the Black Sea Basin

The hydrographic network of the Black Sea basin stretches on a large surface of Eurasia, 22 countries (Albania, Austria, Belarus, Bosnia and Herzegovina, Bulgaria, Croatia, the Czech Republic, Georgia, Germany, Hungary, Italy, Republic of North Macedonia, Republic of Moldova, Poland, Romania, Slovakia, Slovenia, Sweden, Turkey, Ukraine, Western Balkans, the Russian Federation), of over 22 million km2; generally, the Black Sea’s affluent rivers converge to the sea cuvette (rarely, some affluents have another direction, too). The large rivers flow into the sea through deltas (the Danube, the Dnieper, the Don) and through large river-maritime estuaries (the Dniester, the Dnieper), and the small ones flow directly into the sea. Some rivers have simple flowing conditions, of east-European or continental type (the Prut, the Dniester, the Dnieper, the Don), alpine type (e.g., the affluents on the right side of the Danube’s superior course), and complex type—the Danube crossing various morpho-climatic regions. The main characteristics of the rivers from the Black Sea hydrographical basin are [1] (Table 3.1): From the Black Sea hydrographical basin, the first three rivers as far as dimensions are concerned are the Danube, the Dnieper, and the Don. The Danube is the second largest river in Europe (2867 km); it has a hydrographical basin of © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_3

63

64

3 The Morphohydrography and Morphodynamics of the Black Sea

Table 3.1 The characteristics of the rivers from the Danube hydrological basin Basin surface Char. no. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

Network denomination The Danube The Dnieper The Don The Dnister The Bug The Cuban The Rioni The Koruh The Inguri The Codori The Bzyb The Yesilirmak The Kizilirmak The Sakarya

km2 805,300 503,360 422,500 71,990 63,740 61,530 13,390 22,000 4060 2030 1410 36,100

Length (km) % of the Black Sea basin 33.5 20.9 17.6 3.0 2.6 2.5 0.6 0.91 0.16 0.08 0.05 1.49

Flowing volume (km3/year) 2860 2285 1967 1411 857 900 327 500 221 84 – 460

Sediments (mill. t/year) 198.0 52.1 29.1 10.6 3.2 7.5 8.4 4.63 4.86 4.08 3.07 4.93

51.7 2.12 2.5 0.53 7.08 15.13 2.78 1.01 0.60 18.0

78,200

3.25

1151

5.02

16.0

65,000

2.70

790

6.38

–

817,000 km2, including the surface of 15 countries, with a population of over 76 million inhabitants. The Dnieper, the second largest river at the Black Sea (2295 km), has a hydrographical basin of 503,000 km2, and the Don has a length of 1967 km, and a hydrographical basin with a surface of 422,000 km2. To the northwestern part of the Black Sea, the continental shelf is prevailing; it represents a surface of approximately 127,000 km2, i.e., 94% of the total shelf and 30% of the total surface of the Black Sea; the water volume above this shelf is of approximately 6500 km3, i.e., approximately 1.2% of the total water volume of the Black Sea [2]. At this point, the main rivers from the hydrographical basin of the Black Sea are flowing into the Danube, the Dniester, the Dnieper, and the Southern Bug. The Danube (Figs. 3.1 and 3.2) has the prevalent role in the sediments transport process from this area of the Black Sea (having effects up to the Bosphorus and in areas of great depths), and the Dnister, the Dnieper, and the South Bug have a secondary role (transport of sediments into the lagoons) (Table 3.2). According to Romanian scientists Vespremeanu and Golumbeanu [5], the catchment of the Black Sea area is 1,874,904 km2, consisting of: the western and north western basins (1,252,000 km2—82%), the Crimea basins (2729 km2—0.14%), the Caucasians basins (75,000 km2—4%), and the Asia Minor basins (259,550 km2— 14%) (Fig. 3.3). From a geomorphologic standpoint, the Black Sea coast can be divided into 17 main areas, each of them having specific characteristics. Synthetically, the actual aspect of the Black Sea coastlines is thus [6, 7]:

3.1 The Hydrographic Network of the Black Sea Basin

65

Fig. 3.1 Black Sea hydrographic basin. (Source: By courtesy of Dr. Nicolaev and Dr. Bologa, GeoEco-Marina 11/2005 [3])

Fig. 3.2 The Black Sea drainage basin. (Source: By courtesy of Dr. I. Popescu [4])

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3 The Morphohydrography and Morphodynamics of the Black Sea

Table 3.2 The water and sediments input in the Black Sea Length (km) 1. Northwest of the Black Sea The Danube 2860 The Dniester 1411 The Dnieper 2285 The South Bug 806 Subtotal I 1,455,800 2. The Azov Sea The Don 1967 The Kuban 900 Subtotal II 500,400 3. The Caucasian 41.0 rivers 4. The Anatolian 29.7 rivers 5. The Bulgarian 3.0 rivers Total 372.3

Navigation basin (km2)

Water input (km3)

Sediments (thousands t/year)

805,300 71,990 503,360 63,700 255.7

190.7 9.8 52.6 2.6 56.85

51.70 2.50 2.12 0.53

422,500 61,530 42.9 29.00

29.5 13.4 14.80

6.40 8.40

51.00 0.50 152.15

Fig. 3.3 The Black Sea Hydrological Catchment. (Source: Public picture from http://envirogrids. net/indexab45.html?option¼com_content&view¼article&id¼5&Itemid¼16)

3.1 The Hydrographic Network of the Black Sea Basin

67 

– The Black Sea can be sectioned following a fictional axis situated on the 34 300 E meridian in two approximately identical lobes, i.e., the western and the eastern basin. – The Black Sea coastline has a small sinuosity coefficient, with an extremely varied aspect, i.e., slightly jagged and high to the Eastern, Southern, and Western parts, respectively considerably jagged and low to the northern part. – The most important gulfs and bays are: Karkinit Bay (situated in the south-eastern part of the Crimea peninsula), Taman Bay (situated on the eastern coast of the Kerch Strait), Novorossiysk Bay (on the Caucasian coast), Sinop Bay, and Samsun and Eregli Bays (on the southern coast) and the Gulf of Burgas (on the western coast); the biggest estuaries are those of Dnister and Dnieper rivers; Crimea is the sole peninsula, being united with the continent through the isthmus of Perekop; the most visible capes are: Tarkhankut, Cherson, Sarîci, Meganom, Doob, Pitsunda, Ciam, Indjeburun, Baba, Emine, and Kaliakra [6, 7]—the larger island is the Serpent Island (1.5 km2), situated at a distance of 20 nautical miles from the coast, right in front of the Danube Delta; the smaller islands Berezan situated at the entrance of the Berezan estuary, respectively Kefken estuary, at 50 nautical miles east from Bosphorus. – The coastline from the Danube’s mouths to Sevastopol Bay has the aspect of a plain fragmented by valleys with abrupt slopes that end in some places directly in the sea through sea walls, and in other places that end with coastlines; the south coast of the Crimean Peninsula is mountainous and very jagged, and it is composed of the Crimean mountains’ slopes. – In its south-western part, the coast of the Kerch Peninsula resembles a plain with a hilly aspect and, in the north-eastern part, the aspect resembles a hillock; the Kerch Strait is limited to the west by the Kerch Peninsula and the east by the Taman Peninsula; the strait’s coasts are high, except the Taman Bay’s coast, which is low and gradually rises to the inside of the mainland. – The Caucasian coast, situated between the Kerch Strait and Cape Kalender is almost entirely mountainous, a little jagged; in the Tuapse-Ocheamchire sector, the Caucasian peaks are getting very close to the coast, and to the south of Batumi port the Eastern Pontic Mountains chain begins. – The Black Sea southern coast (i.e., Anatolia) stretches from Cape Kalender to the Bosphorus Strait. It is mountainous, the Pontic Mountains chain, with heights of 3000 m, has its surface parallel with the sea coast, at a small distance. The peak’s height decreases gradually towards the strait, so right in front of the strait the coast is low; from the Bosphorus Strait to Cape Kaliakra, the coast is mountainous, due to the presence of the eastern chain of the Balkan Mountains. The mountains are gently decreasing towards the sea, resulting in an inclined plateau between Cape Igneada and Cape Maslen Nos, and from Cape Emine to Cape Kaliakra, the coast is high here and there, abrupt to Batova valley, after that, it decreases slightly in altitude. – The coast between Cape Kaliakra and the port of Midia presents a relatively high seafront, fragmented by prolonged valleys, perpendicular on the coast and occupied by lakes separated from the sea by beach barriers; the Danube Delta

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3 The Morphohydrography and Morphodynamics of the Black Sea

represents the north coast from Cape Midia, and it has the shape of low and sandy coastlines. In the northern part, the Black Sea is connected with the Sea of Azov through the Kerch Strait, between Cape Tekili and Cape Panaghia and in the southern part wibth the Marmara Sea through the Bosphorus Strait (length of 35 km), between Cape Rumeli and Cape Anadolu. From the sea bottom’s characteristic standpoint, the Black Sea is divided into two areas [6, 7]—the north area, characterized by small depths of up to 200 m (especially in the north-western sector), and the south area, with great depths (over 200 m, respectively). The continental shelf stretches to depths of 200 m; afterward, the slope of the submarine bottom is abrupt, except for the north-western sector. The biggest depths are in the central area of the sea. In this part, the sea bottom is very pleated, especially to the southern and eastern mountainside, where a series of extinct volcanic cones have been discovered. Recent studies (Sozanski 1998) have pointed out the presence in the Black Sea of muddy volcanos and of gas fields (Fig. 3.4) [8]. The central part of the Black Sea is considered to have a suboceanic character, and the sea bottom has some peculiarities, represented by an elongated crest from the northern part, and some isolated heights in the central and south-eastern parts [9] (Fig. 3.5). The continental shelf stretches up to 180 km from the coast in the north-west (Figs. 3.6 and 3.7) up to the depth of 130–132 m, (agglomeration shelf), with very small submarine slopes (of 40 –50 in the northern part and somewhat bigger in the southern part, of 70 –90 , respectively). The central depression has a flattened shape;

Odesa Kerch Sevastopol Constanţa

Gas

Novorosiiyk

Gas Varna Gas

Mud vulcanoes Gas

Batumi

Samsun Istanbul

Trabzon

Fig. 3.4 Map presenting the muddy volcanos and the gas fields in the Black Sea. (Modified after Sozansky [8])

3.1 The Hydrographic Network of the Black Sea Basin

0 km

Crimea Peninsula

Black Sea

69 Anatolian Plateau

-10 -20

Fig. 3.5 The N-S profile of the Black Sea basin. (Modified after Romania Geography I, Physical geography, 1983, [9])

Fig. 3.6 Caption. (Source: Modified after public picture: the Black Sea bottom topography constructed from the 1-min DBDB-V resolution dataset of NAVOCEANO. Two different color bars are used to emphasize different depth ranges in the Black Sea: (top) deep water and (bottom) shallow water (200 m). Major rivers discharged into the Black Sea are in yellow [10])

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3 The Morphohydrography and Morphodynamics of the Black Sea

Fig. 3.7 The bathymetric map of the Black Sea. (Source: Modified after public picture from http:// emodnet.eu/2017 [11])

the connection with the shelf is made through a continental slope, affected by landslides, tectonic dislocations, and submarine canyons. The slope or the continental acclivity has the aspect of an inclined plane with slides, between 130 and 2000 m, having the following subdivisions: 



(a) 130–1300 m, characterized by average slopes (tan.) 2 –3 , and some portions   having slopes bigger than 4 –15 (b) Thesubmarine piedmont, at the shelf basal part, between 1500 and 2000 m, with smaller slopes. Due to the diversity of its surrounding terrestrial relief, the Black Sea accommodates many canyons with multiple aspects (By courtesy of Dr. I. Popescu Figs. 3.8, 3.9, 3.10, and 3.11) [4]. The wide-shelf canyons, typical for the northwestern and northern Black Sea zone, are associated with large European rivers (Danube, Dniepr, Don, and Kuban). In lowland conditions, these rivers discharged large amounts of clastic material into the Black Sea basin [4]. In the eastern, Caucasian Black Sea, the narrow-shelf canyons developed. These high-energy canyons have been able to transport sedimentary material with various grain sizes, including gravels, as evidenced by the presence of gravel waves [4]. * We must mention the submarine canyon, located approximately 800 m east from Cape Tuzla, initially mapped in 1965 by Dr. O. Şelariu and afterward by Russian geologists (Fig. 3.12). The forming of the coasts is the result of tectonic factors, sea level variation, sediments’ contribution and character, wave conditions, tide, vegetation, etc. Generally, these represent narrow areas, being transformed through the actions of the marine, earthly, and atmospheric processes. The Black Sea coasts can be classified into three morphodynamic categories, as follows [13]:

3.1 The Hydrographic Network of the Black Sea Basin

71

Fig. 3.8 Large submarine canyons from the western and northwestern Black Sea basin. (By courtesy of Dr. I. Popescu [4])

Fig. 3.9 Large canyons from the northern Black Sea basin, the Crimean area. (By courtesy of Dr. I. Popescu [4])

– Low coasts, of accumulation type (e.g., delta, estuary, lagoon, etc.), most of them being areas of the main rivers: the Danube Delta, with a littoral of 240 km; the estuary of the Dnister-Karkinit Bay (~618 km); Kinburn spit-Island Dolgyi (~20 km); Tendra spit-Island Dzharylgatki (~137 km); Taman-Anapa (200 km, out of which 66 km the Anapa spit); Kolchida (Rioni) delta area of the Cobi, Rioni, Inguri, Supsa rivers; Kizilirmak, Yesilirmak, Sakaraya rivers delta; Diavolska, Kanchya, Provadyska, Batova rivers’ mouth area (~100 km).

72

3 The Morphohydrography and Morphodynamics of the Black Sea

Fig. 3.10 Large canyons from the southern Black Sea, the Anatolian area, Black Sea basin. (By courtesy of Dr. I. Popescu [4])

Fig. 3.11 Bosphorous submarine canyon system, Black Sea basin. (By courtesy of Dr. I. Popescu [4])

– High coasts with seafronts: the north-western area of the Ukrainian coast (from the northern limit of the Danube Delta to Ocheakov—the western limit of the Dnieper estuary, ~232 km); the southern sector of the Romanian coast (from Cape Midia to Vama Veche ~75 km); the northern sector of the Bulgarian coast (from Vama Veche to Cape Kaliakra ~50 km). – The mountainous coast: the coasts of Crimea, Caucasus, Pontic Mountains, Strandja and Stara Planina, Frangensko and Avresko shelves. The Black Sea coasts erosion is determined by factors which can be divided into three categories: planetary (the continuous modifications of the World Ocean, and the general tendency of the sea level rising); climatic (the complex and concerted action of the meteorological and hydrological factors); anthropic (the rivers regularization, the hydro-technical constructions, etc.). For exemplification, it can be shown that the first category of coasts is under the influence of an intense regression process (20–30 m/year in some portions of the Danube Delta’s coast), and those areas were under the influence of the erosion process to a slower one (1–2 m/year) [13]. In conclusion, it can be shown that the most vulnerable coast area of the Black Sea is the Danube Delta coast (240 km, out of which 75 km represent the littoral of

3.1 The Hydrographic Network of the Black Sea Basin

73

Fig. 3.12 The Danube Canyon Source: modified after Paleogeographic map of the north-western Black Sea margin. Individually incised paleochannels identified on shallow seismic profiles were shot by the GeoEcoMar Institute and interpreted by Popescu et al. [12]. Areas characterized by the dense occurrence of buried channels cluster in two main paleo-drainage systems, http://intranet. geoecomar.ro/rchm/wpcontent/ uploads/downloads/2014/11/Lericolais-et-al_High-frequency-sealevel-fluctuations-in-the-Black-Sea.pdf. (By courtesy of Dr. I. Popescu [12])

the Chilia delta, and it belongs to Ukraine, and the remainder littoral belongs to Romania, 165 km respectively) [14]. The complete geomorphological map of the Black Sea (according to Panin, 1977 [14], as well as by Shuisky, 1993 [15] is represented as follows (Fig. 3.13): Romanian researchers (Panin and Ion 1997; Jipa et al. [16]) proposed the following geomorphological division into zones of the Black Sea (Fig. 3.14): In the Technical Report of the Joint Research Centre (JRC), the European Commission’s science and knowledge service, Changes in the Black Sea physical properties and their effect on the ecosystem – 2016, the topography of the Black Sea is presented as follows: the 1500 m isobath is drawn in magenta, and the boundaries of the shelf and deep-sea compartments, separated by the 150 m isobath in green (Fig. 3.15) [17].

74

3 The Morphohydrography and Morphodynamics of the Black Sea

Fig. 3.13 The geomorphological map of the Black Sea [14, 15]. By courtesy of. Prof. N. Panin) Legend: 1—limit between the continental field and the continental slope, 2—limit of the elevations; 3—basis of the mountainous structures; 4–5—morphological elements inside the continental slope; (4— stages; 5—heights); 6–8—limit of the deep zone of the sea (7—it corresponds to the height base; 8—it corresponds to the base of the mountainous structure); 9—axes of the mountainous crests; 10—axes of the depressions; 11—faults, 12—the areas where the continental platform margin does not correspond to the limit of the continental domain; 13—the margin of the abrasion-accumulation surfaces, of another age or depth than the shelf margin; 14–21—genetic types of the bottom surface (14—abrasion-accumulation type in the area of strong waves’ action); 15—the same thing, in the area of weak waves’ action; 16—type of accumulation, but keeping the primary irregularities; 17— type of accumulation, smoothing the primary irregularities in the areas with lower mountainous relief; 18—the same thing, in the areas with lower hilly relief; 19—accumulation plain without waves action; 20—areas of tectonic fracture; 21—type of erosion—accumulation (under the action of the bottom currents); 22—submerged erosion witnesses; 23—emersion erosion witnesses; 24— rocky ridges; 25—slidings; 26—erosion valleys; 27—tectonic valleys; 28—old submerged abrasion terraces; 29—heights of tectonic nature; 30—depth of the continental platform’s margin and of the smoothing surfaces; 31—depths in m; 32—average depth of the surfaces

3.2

The Black Sea Morphodynamics

The Black Sea is a deep basin with steep slopes. The isobath of 100 m is almost entirely parallel to the seashore at a distance of 1.5–6 nautical miles. Only in the west and north-west and at the entrance into the Kerch Strait this isobath exceeds 20–50 nautical miles from the seashore. In the western basin, between Cape Emine and Cape Yevpatoriya, the 100 m isobath is almost linear (from this to the shore the

3.2 The Black Sea Morphodynamics

75

Fig. 3.14 The geomorphological division into zones of the Black Sea. (By courtesy of Prof. Panin and Dr. Ion (Jipa et al. [16]))

Fig. 3.15 Topography of the Black Sea, 2016. (Modified by public picture [17])

depths gradually decrease). Isobaths of 200 m, 500 m, and 1000 m are passing by a 100 m isobath, keeping a close configuration to it. The seabed at these depths in some places reaches 14 . Switch to a depth of 1000 m is achieved gradually. Near the coastline, with shallow waters, there are sandy submarine banks parallel to the shore. Their density depends on the breaker’s force: if the breaker’s area stretches into the sea, the waves can form in a higher number than in a common coastal area. The initial movement of the submarine sand waves is related to the critical depth (twice the height of the waves) of the Black Sea, this phenomenon occurring at depths of 4–6 m. Next to the rocky shores of the Black Sea, the bottom consists of rocks and gravel, and lower portions of the sandy bottom dominate the shore. At depths of 20–30 m,

76

3 The Morphohydrography and Morphodynamics of the Black Sea

the sand is replaced with sandy silt. In areas of greater depths, the bottom has a silt loam character. At a depth of 200 m in many places, scallops can be found in high concentrations. In the north-western part of the sea, between the mouth of the Danube and Cape Tarkhankut, at depths of 50–60 m, large areas of the bottom are occupied by marine vegetation. At depths greater than 200 m, the bottom consists of thick, black mud, saturated with hydrogen sulfide, which in contact with air quickly becomes gray. At depths greater than 1500 m, the gray-blue mud in some areas is mixed with clay.

3.2.1

The Coast Aspect in the Western Basin of the Black Sea

The coastline in the western basin of the Black Sea is relatively sinuous, as there are capes that protrude far into the sea (e.g., Cape Tuzla, Cape Shabla, Cape Kaliakra) and bays that are entering far into the land (for example Burgas Bay), as well as other zones (e.g., Gura Portiţei and the coastal estuaries) that contribute to a greater degree of the coast’s sinuosity. The Crimean Peninsula has special importance in the zone’s hydrography as it divides the Black Sea waters into two basins, of east and of the west, that are almost identical. In this basin, there are a few islands, out of which we mention the Serpent Island in the northern part and Kefken Island in the southern part, located near Bosphorus. As regards the coast aspect, it can be shown that it is diversified, as follows: it is mountainous in the northern part, with very steep coasts, almost vertical, alternate with those relatively low, with sandy beaches; then, advancing to the north, the differences become less obvious, succeeding individual formations of abrupt rocks reaching the sea, too; in the area of Cape Emine, the coast is again rising, and from Cape Kaliakra to the north, up to Cape Singol, the coast has the aspect of a not-veryhigh sea wall, having sandy beaches at its base. From Cape Singol to Cape Midia, the coast is low, sandy, then, at Vadu it has the aspect of a relatively high sea wall. The northern part is very low, in this area being located the Danube Delta, the coastal lakes, Dniester’s and Dnieper’s estuaries. Traditionally, the Ukrainian Black Sea coastal zone and the Sea of Azov are divided into eight areas based on coastal morphology and processes [18]. From the Danube Delta to Sevastopol Bay, the coast is a little high; the zoning relief is represented by a plain that ends through sea walls in the sea, and in certain places, it ends through sand coastlines that are separating estuaries or salty lakes from the sea (some of them are entirely closed and others are temporarily connected to the sea, but some estuaries have a permanent exit to the sea). The south-western coast of the Crimean Peninsula to Sevastopol bay is lower, abrupt, consisting of reddish rocks. Nearby Sevastopol port, the rugged coast is yellow; it is almost entirely without vegetation; also, in the coastal region there are a few lakes, most of them with salt water. In the north-western part of the Black Sea, the coast is the most prone to erosion, as follows: in the portion from Cape Burnas to Bugansky

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Buoy, the erosion is 3–6 m/year; in the Sonzheiskiy Lighthouse area, the erosion is up to 2 m/year; from Dnister estuary to Odesa Bay, and further on, it is under 1 m; at the Yuzhny Bug river outlet, it is 0.5–1 m/year, in Zselezniy port district and the south-western part of Giarîlgach Bay, it is 2,5–3 m/year; the erosion of the coast from the base of Bakalsk sand area is 3–4 m/year; and in the area of Evpatoria Light, the erosion is 2,2–5 m/year (on the portion from Saki town to the exit of Sevastopol Bay, the erosion is 1,5–2 m/year). In the east of Sevastopol Bay, the coast begins to rise visibly. In the area of Cape Fiolent, to Feodosia port, there are two, even three, parallel chains of mountains. In some zones (from Cape Sarich to the end of Ialta Bay), the mountains are a little farther from the coast, and the acclivities become more gentle. The Kerch Peninsula, which represents the eastern end of the Crimean Peninsula, is divided by a not-verytall mountain remnant, in two portions, respectively, the north-east and the southwest. The north-eastern portion is hilly, and the south-western portion is like a plain with low hills in some places. The coasts of the Kerch Peninsula are abrupt almost on their entire length. The erosion in the southern part of the Crimean Peninsula is gentler (0,2–0,3 m/year); smaller rivers cross the coast, and the bottom’s nature consists of submarine reefs and rocks [18]. The Romanian coast of the Black Sea is located in the northwestern part of the sea, having an opening of about 210 km, respectively between Musura mouth (45 120 N lat, 29 400 E long)—the border with Ukraine to the north, near the Danube Sulina’s Mouth (Fig. 3.11), and the conventional line that passes through the southern part of Vama Veche (43 440 N lat, 28 350 E long)—the border with Bulgaria to the south [19]. In the sector of the Romanian coast, there are as major morphohydrographical entities: the Danube Delta and the river-marine and maritime estuaries: Agighiol, Babadag, Taşaul, Techirghiol, Tatlageac, and Mangalia. The coast is divided into two major physiographic units. The northern unit is part of the Danube Delta Biosphere Reserve, Europe’s largest nature reserve, rich in wildlife, and the southern part comprises Constanţa, the biggest Black Seaport, plus an almost uninterrupted chain of a tourist resort, alternating with town and harbors [19]. The Black Sea Delta (Lat. 44 250 N lat, 45 300 N long, and 28 450 E lat, 29 460 E long) is located between the Bugeac plateau, to the north, and the Dobrogean platform zone to the south. It has been formed in the place of an old marine bay (Halmyris), which was isolated in prehistory by the sea, by Letea, Caraorman, Crasnicol, and Lupilor banks, and clogged in its northern part by the silts brought by the Danube river. The clogging process continues at present, also. Razim lagoon was separated from the sea as a result of Perişor, Chituc banks formation [13]. The Danube Delta consists of the river delta and river-maritime delta, and it is located between Musura Mouth and Cape Midia. The coastal lakes were formed either through barring with offshore bars of the not-very-deep marine bays (e.g., the lagoons Razim-Sinoe-Goloviţa-Zmeica, and Mamaia-Tăbăcărie), or through marine waters flooding of the inferior watercourses of some valleys, that subsequently had been entirely or partially barred through sand cordons (the estuaries Agighiol,

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Babadag, Ceamurlia, Tuzla, Gargalâc, Taşaul, Agigea, Techirghiol, and Mangalia) [20]. It is supposed that the tectonic movements have influenced the forming of the lakes: Babadag, Taşaul, Mamaia, Mangalia [21]. Under the influence of several natural factors, but also of an anthropic nature, along with the Romanian littoral of the Black Sea, a series of morphologic modifications take place, such as the alternation of some abrasion or depositing processes along the coastline, erosions, or sedimentations on the coastal submarine slope. The analysis of these processes takes into account a larger zone of sea-ground interaction, with the stipulation that in the adjacent submarine field appear important hydrodynamic actions, with direct implications in the coastal hydrography. These are taking place under the action of the deformed and surf waves, as well as in the presence of a silt inshore high tide, oriented and maintained through the dynamics of the seawater. From a morphological point of view, in an almost unanimous understanding, the Romanian littoral of the Black Sea is divided into a northern deltaic-lagoon section, with an aspect of low accumulation sea coast and a southern section, of a seashore with active abrasion sea walls, separated by Cape Midia. The Danube Delta can be divided into three big depositing systems: the sub-aerial deltaic plain ~5,800 km2, the front delta ~1,300 km2, and prodelta ~6000 km2 (according to Panin—1989) (Fig. 3.16). Considering the actual morphological processes, of accumulation-erosion, the differentiation point can be placed at Cape Singol, making evident in this way a sector of the intermediary coast—of transition, mainly marked by the Mamaia beach barrier. The delimitation of this intermediary coastal sector is justified by the inactive character of the retired sea wall in the western part of Mamaia Lake and, therefore, a halving of the coastline on a distance of about 125 km, as well as by some local characteristics, mainly depending on the important deviations of the silt current towards the open sea, as a result of the Midia port’s dams extension into the sea [22]. In the northern sector of the Romanian littoral (representing 63% of the total length of the coast), with the aspect of low “coast” and constituted of associations of offshore bars that consist of fine sands, of a quartz-micaceous type, the dominant morphological processes should be those of an accumulative nature. Here there is an alternation of accumulation and erosion on the coastal submarine slope, in space as well as in time, concerning the position of different coastal portions, the solid flow variation of the Danube river, the oscillations of the sea level, the direction variation and, the wind intensity [23]. Therefore, it can be established that, lately, marine accumulation has gradually given up in favor of the erosion processes happening at the coastline, according to some bathymetric and sedimentological changes in the predeltaic submarine field. These phenomena can be met in several sectors, such as [24]: – Gârla Împuţită sector: Here, as a result of the prolongation of Sulina navigable canal, the erosion produced by waves is strong, thus causing the withdrawal of the inshore cordon by 8–10 m per year.

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Danube Delta’s depositing system

30 40

Pr od e

lta

Deltaic Plain Sulina Fluvial Marine

Delta

Tulcea

Fron t

Izmail

Cape Midia

Shelf Constantza

30 40 Mangalia

a 1 b c

a 2 b c

200 500

3 4 5 100

150

Viteaz Canyon

Fig. 3.16 Depositing systems of the Danube Delta (according to Panin-1989) Legend: (1) deltaic plain: (a) river deltaic plain; (b) “marine” deltaic plain; (c) (2) front delta: (a) front delta platform; (b) relicts of Sulina delta and front delta; (c) front Delta slope; (3) prodelta; (4) shelf; (5) bathymetrics. (By courtesy of Prof. N. Panin)

– Ciotica-Perişor sector: Under the groin effect of the elongation towards the south-west of Sacalin island and the lower flow of Sfântul Gheorghe arm is producing a withdrawal of the coastline by a rate of 7.5 m per year; Sfântul Gheorghe arm overflows a quantity of water with alluviation of 800,000 m3/year, the result contributes to the coast’s advance along a few kilometers, near Sakhalin Island. – Portiţa-Chituc sector: A translation towards the west of the coastline over the lacustrine formations is mentioned. The oozy deposits, reaching the sea-coast, are destroyed by the waves, thus accelerating the withdrawal of the shoreline by a rate of 10–15 m per year (particularly, at the beach barriers of Sinoe la-goon). In the

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northern parts of Chituc’s natural levee deposits, a strong erosion is still in progress, but in its southern parts, the advance of the land into the sea under the incidence of the alluviation flow returned to the coast is noticed, a deposit also caused by a barring effect of Cape Midia. In this way, an accumulation rate of 6–8 m per year is realized [22]. Deposits along the coast, aside from those mentioned above, are also noticed in the southern part of Sulina maritime canal, in the river mouth area of Sfântu Gheorghe arm—where, the morpho-hydrographical evolution is more complex than in the Periteaşca zone, where the advance rate of the coast is 8 m per year. As this rhythm is analyzed over short periods, of about a few years, one can appreciate that here begins a decompensation of the alluvial material in relation to the sector extremities, where abrasion processes take place. Recent research [14] has shown regression of the coast in this area by 3–5 m per year in the last 15 years—in the previous 2,500 years, the erosion tendency has a feature of permanence in the area; therefore, it had caused the Delta coast’s withdrawal from Sulina arm’s zone by more than–12 km. Besides, in the last hundred years, coast evolution in the Sfântu Gheorghe area (Sahalin Island, respectively) has undergone continuous withdrawal of its line (Fig. 3.17). Concerning this phenomenon, in the last 20–25 years, as a result of the hydro technical barrages at Porţile de Fier I and II, the sediments flow of the Danube has considerably decreased, by around 50%, at a level of 20–30 million tons/year, out of which sand represents 10–12% [2]. According to Romanian scientists Bondar and Iordache [25], the multiannual average water discharge at Orsova was 5,950 m3/s; at Oltenita, 6,000 m3/s; and at the entrance in the Danube Delta, 6,220 m3/s. The multiannual average suspended sediment discharge at Orşova was 1,110 kg/s; at Olteniţa, 1765 kg/s; at Brăila, 1,800 kg/s; and at the Danube Delta apex, 2,110 kg/s [26] (Figs. 3.18 and 3.19). In contrast with the strongly eroded northern sector, the sector in the southern part of Chituc’s natural levee deposits presents accumulations owing to sand transport from the northern sectors affected by this process. This situation is favored by its location, as well, being supported by Cape Midia, which in this case plays the role of the groin, retaining a considerable quantity of the alluviation transported by the coastal currents. Along the coastline, the average accumulation rate increases towards the south by 6–10 m per year. In conclusion, although from a morphogenetic point of view, it is considered to be of the accumulation type, the deltaic lagoon coast from the northern sector is rather complex. Also, it has great mobility in time and space, with strong erosion in some sectors, alternation with accumulations to a lower extent, in direct correlation with the natural levee deposits’ displacement conditions, too. Therefore, the accumulation processes are prevalent on a length of 25 km, the erosion processes are met on a range of about 90 km, and the coast is relatively stable on about 20 km [16]. The section of the transition coast between Cape Midia and Constanța is characterized by certain morphological lability; the dam of the open sea of Midia port is supported on Cape Clisargic, oriented in the north-south direction and gradually

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Sahalin - Zatoane Sector 1898-2010

Legend Coast Line Catuneanu map1898 Austrian chart1910 CSA chart 1962 Topographic map1975 Topographic map1.25,000 Soviet chart1980 Ortographic map2004 SPOT shoreline 2007 Shoreline 2008 Shoreline 2010

Danube Delta

Sahalin Island

Black Sea

Fig. 3.17 Sahalin –Zătoane Sector between 1898 and 2010. Source: Coastal dynamics and sedimentology studies, Technical assistance for project preparation, Priority Axis 5, Implementation of the appropriate natural risk prevention structure in most at-risk areas, Key Area of Intervention 2, Reducing coastal erosion. (Modified from a public picture from Romanian Water Basin Administration Dobrogea Litoral, 2011)

Fig. 3.18 The variation in time of the Danube annual average water discharge and of the multiannual average water discharge at Orsova (Series 1 and 2, respectively) and at Ceatal Ismail (Series 3 and 4, respectively) between 1840 and 2013. (By courtesy of Dr. C. Bondar [25])

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Fig. 3.19 The variation in time of the total discharge of sediment (fine and coarse) annual average Rmea (1, 3, 5), and multiannual average Rmeam (2, 4, 6) of the Danube, in hydrometrical sections Bazias (1–2) km 954, Gruia (3–4) km 858, and Ceatal Ismail (5–6) km 80.5 between 1840 and 2012. (By courtesy of Dr. C. Bondar [25])

prolonged since 1936, (when it had only 800 m), up to the present time (2 km), having the last section oriented in the south-south-east direction; it represents a real obstacle for the natural levee deposits’ currents, in the sense of their deviation towards the open sea. To the groin effect of this dam, almost parallelly oriented to the coast in its terminal part, moving the alluvial material away, therefore determining erosions in portions of Mamaia beach barriers, is added a contrary effect, of the intake of a certain sand volume (by diffraction, transversal movements of the wave currents, etc.) to the south dam’s refuge of Port of Midia. The retention of the alluvial material is realized to the detriment of the sand reserves from the southern part of Mamaia coastline and of the adjacent submarine slope. In this way, a small sea deepening is produced, enough to disturb the sedimentary balance of the submarine profile of the area. Consequently, except for a portion of reduced accumulation at the south dam of Port of Midia, in the sector of the transition coast, the coastline is withdrawing with an average annual rhythm of 2 m, the erosion processes towards the south direction are advancing. These determine coastal protection measures to be taken in front of Mamaia’s resort. Cape Singol headland that stretches into the open sea like an abrasion rocky platform produces a new deviation, a departure from the coast, and the dispersion of the alluvial material. The southern section of the Romanian coast of the Black Sea, characterized as a zone with terraces and estuaries, knows a morpho-dynamic that depends on its lithologic structure and on the waves’ direct effect, in the conditions of a more reduced alluvial supplement. Generally, the coast with sea walls, from the south of Constanţa port, in its unimproved portions is affected by a series of gravitational and degradation

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processes—landslide, breakdowns, suffusion caused, largely, by the groundwater’s horizons from the base of the loess horizons. However, in the areas where the sea wall is interrupted by the sand cordons of the lagoon and estuary bays, the emersed and submerged beaches are suffering modifications in their balance profile due to the sea motion conditions. Beginning with the Constanța–Agigea–Eforie Nord sector, the inflow and the influence of the alluviation flow is felt less and less; as a result of the construction of Constanța South port’s dams, a beach located south of cape Agigea knows a strong erosion process, extended and gradually intensified towards the south direction. In the Eforie Nord–Techirghiol Lake sector, generally reduced changes can be observed at the coastline, but with some notable erosion in the central portions of Techirghiol lake’s coastline. In the Eforie Sud–Tuzla sector landslide and weathering processes of the coast can be observed, favored by the phreatic horizon, processes intensified during the wet periods of the year or when the storm waves affect directly the sea wall, that could determine in such situations the coast’s withdrawal by 0.5–1.0 m/year13. In the Tuzla–Costineşti sector the abrasion is strong, associated with breakdowns and gradual landslides, and in the coastline of Costineşti Lake, the erosion rhythms of the beach can reach up to 2.5–3.5 m/year. In the Costineşti–Mangalia sector, the sea wall is also subjected to some abrasion processes, resulting in structural microterraces or abrasion niches north of Tatlageac lake, or the coast withdrawal through abrasion by an average rhythm of about 2 m/year, in front of Resort Olimp. Postolache and Diaconeasa (1995) show that in the last years, in the northern sector of the Romanian littoral, the erosion almost became generalized, and the total loss of the coast was of 2356 ha (45–80 ha/year); in the southern sector, the phenomenon is less developed, but it has determined very important losses in the area of Mamaia beaches (approximately 65.5%) and of Eforie beach. Furthermore, the coast withdrawal in the delta area was revealed [26]. By the last research (according to Giosan et al. [27]; Stănică et al. [28]), the sediments dynamics at the Romanian Black Sea littoral is as follows: in Sulina area—Cape Midia there is a big tendency of retreat from the coast under the waves energy influence, and of their big angle of attack over the shores, as well as of the low refraction, and the submerged slope with a relatively small inclination; in the northern part, this zone is isolated by marine impermeable hydro-technical structures (the Sulina dams), and in the southern part (the Midia dams), the coasts are modified depending on the sediments’ redistribution from a sector to another, depending on the transport current along the coast; in Sulina–Sf. Gheorghe zone two cells of the net sedimentary transport were determined, a sector located close to the south point of the Sulina dams, with an average rate of sediments transport of 190,000 (130,000 m3/year) and a sector to Sfântu Gheorghe’s mouth, with an average rate of 620,000 m3/year (415,000 m3/year, calculated up to the depth of 6 m, and 830,000 m3/year, up to the depth of 12 m); through Sfântu Gheorghe’s arm, around 800,000 m3/year of sand is discharged; the sediments transport increases from around 900,000 m3/year at south of Sfântu Gheorghe’s mouth up to 1,750,000 m3/ year in the median sector of the Sahalin Island (in the southern part of the island, the

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sediments’ transport has the value of 900,000 m3/year); between Ciotica and Perişor, the potential net transport has an average rate of about 270,000 m3/year (180,000, calculated up to the depth of 6 m, and 360,000 m3/year, up to the depth of 12 m); between Chituc and Midia, the transport rate increases from the value 0–1,075,000 m3/year, in the north of the natural levee deposits, and decreases up to 775,000 m3/year at Midia [28]. The Bulgarian coast of the Black Sea consists of the eastern prolongations of Stara Planina Mountain, and in the northern part of Cape Kaliakra, the height of this rocky coast decreases gradually. It is composed of circa 60% rock cliff, circa 30% beaches, some with backing dunes, and 10% low-lying parts of firths and lagoons with two large bays, Varna and Burgas [29]. The rivers from the Bulgarian littoral are nonnavigable, most of them are flowing into salty estuaries, which have connections with the sea through narrow mouths. It can be shown that the western coast of the Black Sea (length ~600 km, i.e., 15% of the total length of the coasts) is divided from a geological and geomorphological point of view, of the coastal currents circulation, and of the alluvial transport perspective, into three morphodynamic categories: (a) Low accumulation coasts: The Danube Delta, the area of the Devil, Kamcha, Provadiska, and Batova rivers (~280 km). (b) Erosion coasts or cliffs at the edge of the plateau or the plain, developed in deposits of loess or similar deposits, that, generally, cover calcareous deposits (Pontic, clayey, Meotian) and Sarmatian limestones; in the front of the sea walls there are often accumulated sediments that form narrow beaches (between Cape Midia and Cape Kaliakra). (c) Coasts of the mountainous relief, characterized by sea walls, marine terraces, gravitational slidings, and beaches with sediments of sand or gravel: Stara-Planina Mountain and Strandja Mountains and Frangensko and Avrensko plateaux. The southern coast is abrupt and rocky, almost on its entire length, or it ends with terraces into the sea. Also, even if rarely, there are low and sandy portions. On this portion of the western basin of the Black Sea, there is a multitude of nonnavigable rivers in the superior part, which is very quick on the middle course and quiet at the river’s mouth in the sea. The sea coast is not very high on the west side of the Bosphorus Strait. The capes in this area are abrupt.

3.2.2

The Sea Bottom’s Relief and the Depths of the Western Basin of the Black Sea

Depending on the sea bottom’s relief character, the western basin of the Black Sea is divided into its northern zone, with low depths, respectively, of up to 100–200 m and the southern zone, with over 200 m depths, both of them being oriented according to the direction of the geographical parallel.

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Beginning with the Neogene period and in the course of the entire Quaternary, being disposed at the edge of the Russian platform, the northern zone had undergone descents and rises relatively slowly; the result is the more uniform and slow variation of the depths; also, the fact that in the area there are many small islands and sandbanks demonstrates the existence of an actual diving process [30]. The deep regions are represented by the edge of the Russian platform, separated by the adjacent dry ground and which subsided as a result of a recent fall. The continental shelf has one of the biggest widths in the north-western sector (with a surface of 63,900 km2 and a depth lower than 200 m) [31], where an isobath of 200 m departs from the coast at approximately 180 km; in the south-west, this is getting narrower to only 50 km, and in the south, it often gets only a few kilometers from the coast. After the continental shelf, the depths are growing relatively quickly, especially in its southern part, where they reach 2000 m, and they are at 45–60 km from the coast. The central part of the western basin has an almost uniform aspect, with depths of about 2000 m, this fact representing a peculiarity of the sea bottom’s relief [32]. The bottom’s slopes on the continental shelf are relatively small, from   0 300 to 5 , and on the continental acclivity, they are bigger.

3.2.3

The Sea Bottom’s Nature in the Western Basin of the Black Sea

From the point of view of the sea bottom’s nature, in the western basin of the Black Sea, there are two distinct zones, thus: the northern sector, where there are sediments characteristic for the east-European platform and the southern sector, with sediments homologous to the geosyncline formations of the geological past [19]. The sediments in the western basin of the Black Sea are divided into two groups: sediments from low depths, or of the oxygenated zone, that exist on the continental plateau; and the second group, the sediments from high depths, disposed in the zones with sulfide hydrogen. The sediments from the low depths are divided as follows: coastal (they cover the coastal zone) and oozy (they are located on the deeper parts of the continental shelf). In the coastal zone can be distinguished rocky, sandy, and claysandy formations. The rocky ones are met in the areas where the deposits are washed by the currents or are represented by large fragments of material, formed as a result of the abrasive action of the sea. The sandy formations start from the beginning of the coast base, or the inferior limit of the rocky deposits and they reach on average up to the depths of 30 m, and in some cases up to 40–50 m (Fig. 3.20). The nature of the actual sediments from the western basin of the Black Sea is as follows: the oozy ones continually substitute the sandy ones: Mytthilus along the coast, the sea bottom is mainly formed by sand deposits, by sandy silts at a certain distance from the shore, and beginning from 200 m and up to closely 1500 m depth, the black silt is usually met. The calcareous silt is reached on a vast space, under 1500 m deep, and, at the biggest depths of the sea, the sea bottom consists of a

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Fig. 3.20 The sea bottom’s nature in the Black Sea western basin

homogeneous grey and utterly nonstratified clay [33]. The intensity of the accumulation of the organic substance on the Black Sea’s bottom is very high (according to some calculations, the layer of grey clay of 1 m thickness has formed over 5000 years, and the quantity of the organic substance that is accumulating daily on 1 km2 of the bottom is 6 tons).

3.2.4

The Coast Aspect in the Eastern Basin of the Black Sea

The eastern coast of the Black Sea is divided between the Russian Federation, Georgia, and Turkey. The Russian Black Sea coast anthropogenetic development, both past and present, is virtually defined by physiographic factors, especially the Caucasian mountain ridge that stretches along that coast. These mountains are the cause of the reduced transport networks and the complexity associated with any settlement development. A significant part of the population lives on the coastal strip, which houses important communications, as well as large and industrial construction complexes. The Russian Black Sea coast is from Kerch Strait [34] to

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the Psou River. On this coast, three large ports are located: Novorossiysk, Tuapse, and Taman. The Black Sea’s north-eastern coast is mountainous, reaching the highest height in the region of the Port of Sochi. Beginning with the Port of Anapa, the Caucasians mountain chain stretches up to the Kodori river valley, where it is completely withdrawn from the shoreline. The highest peak (3240 m) of the coastal mountains is Ciugus peak (Lat. 43 480 N, Long. 40 130 E). The Black Sea coast, respectively from the Port of Anapa up to the Port of Novorossiysk is generally a rocky one, and its erosion is insignificant. The mainland portion between the Port of Tuapse and the Port of Sochi, composed of rocks with different hardness, is continuously and uniformly eroded under the action of the sea waves. From the Port of Sochi up to the Port of Ochamchira, the coast is composed of different rocks and with beach portions of different widths. The beaches consist of solid deposits, carried by rivers and mountain torrents. The most eroded coasts are those situated in the area of the Ports of Adler, Sukhumi, and Ochamchire (1–1.5 m per year). The shoreline that does not go through erosion is the one situated between the Inguri and Rioni river mouths, where the sediments were brought out, deposited by these rivers and the depths are small. In the north part of the Port of Poti and the Batumskaya bay, accumulation of sediments is observed. In the south part of the Kobuleti town, the coast becomes mountainous again, reaching a height of 1500 m in the Batumi port area. From the Kerch Strait up to Cape Batumskiy, the Caucasian coast of the Black Sea is extended to the SE direction for a length of 350 nautical miles, and it is almost entirely mountainous. The Caucasian mountainous chain, whose peaks are particularly high, i.e., reaching heights of over 2000 m, is approaching the coast between the ports of Novorossiysk and Sukhumi. The Eastern Pontic mountains begin from south of Batumi port. Throughout their length, the mountains are furrowed by a significant number of gorges, valleys, rivers, the largest river being the Rioni River, which flows into the sea in the district of the port of Poti. The low coastal areas are in the North-Western part of the port of Anapa, but also in the northern and southern parts of the port of Poti. Gebeus, Lysaya, Bolshoy Pseushkho, Boztepe, Zhemsi, Turetskaya, Shapka, and Olen peaks are considered reference points. The most important ports on the Georgian coast are Sochi, Poti, and Batumi. These ports are shelters against the winds from the sea. However, the standing inside them asks for maximum attention and care from the seafarers towards the local winds (bora, tiagun), and sometimes the vessels’ entering or exiting is impossible. The Caucasian coast is associated with very narrow shelf areas. In the BatumiKobuleti, SE of Sukhumi and Adler-Pitsunda zones the shelf is less than 5 km wide. In these areas, the canyon’s heads incise the narrow shelf and are located in close vicinity of the river’s mouth. The shelf is wider and the continental slope gentler descend slope in the Pitsunda-Sokhurni marine area and between Kodori and Inguri canyons. This is why the canyons from these areas occur 25–35 km offshore [4]. The Black Sea southern coast also has a mountainous character, including the Eastern and Western Pontic Mountains, forming one massif. The greatest heights of

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3 The Morphohydrography and Morphodynamics of the Black Sea

these mountains are in the southern and south-western parts of the port of Batumi. To the western part, the height of the mountains decreases gradually, reaching up to 450 m in the straight line of Istanbul Strait. The southern coast, on almost its entire length, is steep and rocky, or it is often ending with sea walls facing the sea, and rarely low and sandy portions that come out into the sea can be encountered. The rivers from this area are not at all critical for navigation. In the western part of the Strait of Istanbul, the coast is not too high, and it has a reddish color. The Black Sea southern coast that represents the northern coast of the Anatolian Peninsula called the Anatolian coast extends from Cape Kalender to the Strait of Istanbul, having a length of 600 nautical miles. Along Anatolia’s eastern coast, i.e., from Cape Kalender to Cape Işıkli (41 060 N, 39 250 E), stretches a high mountainous chain, consisting of Kacikar Mountains (40 500 N, 41 100 E) of 3,937 m height and Suiudag mountains of 2,930 m height. Near these mountains, one can see well the heights, such as Mount Boloko (41 300 N, 41 380 E), of 1532 m height, Mount Ciha (41 220 N, 41 250 E), Ayana Mount (40 590 N, 40 300 E) of 878 m height, and the heights situated near Trabzon Port. The middle part of the Anatolian coast, i.e., from Cape Boztepe to Cape Işıkli is mountainous too, but lower. Here, the mountains are notched by the valleys of Terme and Kizilirmak’s rivers. As reference points, one can consider Kayasis Mountains (40 530 N, 39 060 E), Bakacak, Kuşkayasi (41 270 N, 35 300 E), and Nébian heights. Anatolia’s western coast is mountainous from Cape Boztepe to the Strait of Istanbul. The mountains gradually decrease in height up to the strait and in this straight line the coast is steep. The strip near the coast, located between Inebolu and Ereğli Cities, differs from the rest of the coast through the parallel valleys and hills covered by forests. Here, one can see well several hills: Tana, Tiurbekaya, Akiazi, and Kiziltape. On the Anatolian coast, the main Turkish ports are found: Trabzon, Tirebolu, Giresun, Samsun, Sinop, Inebolu, Zonguldak, and Ereğli Amasra. These ports are fully opened to the north-west, north, and north-east winds.

3.2.5

The Sea Bottom’s Relief and the Depths of the Eastern Basin of the Black Sea

In the area of Novorossiyskaia Bay, the depths are uniform, not exceeding 20–36 m. Near the coast, approximately on the 10 m isobath, the depths decrease sharply. The nature of the bottom in the northern part of this bath consists of clay, mud, and shells, and in the southern, mud, sand, and stone [6]. At a short distance from Cape Doob (2.2 nautical miles), there are the Eastern, Western, and Northern Penay banks, with rocks and 6–20 m deep water (minimum depth of 5 m is near the Eastern banks). The submarine canyons located close to the Caucasian coast are the most renowned in the Black Sea area. In this area, a close relationship appears to exist

3.2 The Black Sea Morphodynamics

89

between the canyon and the rivers. The major canyons of this area (Bzyb, Kodori, Inguri, Rioni, Supsa, and Chorokhitcoruh) are all associated with rivers [35]. Along the coast, the depths are great, except in the Tamanskiy peninsula area, where the depths are small. The described coast is less notched. Several lagoons and large bays are penetrating the central and the southern part of the coast. Few gulfs and small bays are entering into the Anatolian coast, being open to winds from the northern direction. The best places for anchorage are Sinop Gulf, Rize, Akçaabat, Samsun, and Ereğli bays. The river deltas, especially Yesilirmak, Kizilirmak, and Sakarya, are increasingly entering the sea due to the high silt deposits. In front of those deltas, a gradual change in the depths and the formation of the sandbanks were found. During spring and autumn, the muddy waters of these rivers get into the sea up to a distance of 5 nautical miles from the coast. Along the Anatolian coast, there are great water depths. The greatest depths, near the coast, are between Cape Kalender and Cape Işıkli (41 060 N, 39 250 E), and between Amasra Gulf and Ereğli Bay. The isobath of 500 m is getting closer to the coast, in some places, at a distance of up to 1.5 nautical miles. The large ships can navigate along the coast, at a distance of 1.5–2 nautical miles, except for the sector between Cape Iasun and Cape Bafra, where the distance must be at least 5 nautical miles. In the places where the coast is cliffy, there are reefs, but at depths of 10 m and no more than three cables distance from the coast. In areas where the coast is sandy or gravelly, the depths decrease evenly to the coast. There is a sudden change in depths when sailing along the coast of Kizilirmak and Kadzadere river mouths. Near this coast, the sea bottom generally consists of mud or sand, and only in some areas it consists of shells and stone. In the case of shallow waters, the sea bottom consists of sand. The Anatolian zone is the largest Black Sea mountainous coast, with a 900 km east-west extension. The steep slope and shelf areas (Eregli-Inabolu and Fatsa-Rize) of 2–4 km width alternates with less extensive areas of a larger shelf (7–10 km width in Fatsa-Sinop and Eregli-Ketken marine zones) and gentler slope, associated with deep-sea fan buildup. The main canyons (Sakarya and Yeshilirmak) appear in the milder slope areas. They have a higher dendritic trend, showing a system with the main channel thalweg and several limbs [36].

3.2.6

The Sea Bottom’s Nature in the Eastern Basin of the Black Sea

In their paper Black Sea Basin: Sediment Types and Distribution Sedimentation Processes, the scientists Oaie et al. (2005) present the sea bottom’s nature in the eastern basin of the Black Sea as follows: the Kerch area, between Ukraine and Russia, the surface bottom sediments are dominated by mud, silty mud, and sandy silt. Near the coast, the bottom sediments are mixed with many shells and shell

90

3 The Morphohydrography and Morphodynamics of the Black Sea

fragments, oxidized on the surface. The sediments from the Georgian coast are represented mainly by mud and silt, greatly disturbed by biological activity. Similar sediment types, with the local addition of a significant sandy fraction, are present in the Sinop area, Turkey. Shell detritus is a constant component of the sediments. The presence of oval-shaped mineral grains (1–6 mm) in the mud and shell detritus indicates dynamic conditions of sedimentation. The dominance of shell detritus over whole mollusk shells is a characteristic feature of a shallow environment in littoral and sublittoral zones, with a more active influence of waves. The laminated sedimentary sequences, Unit I—coccoliths ooze and Unit II—sapropelic mud, appears continuously in the eastern Black Sea abyssal basin and can be traced throughout the entire basin. Occasionally, turbiditic layers emerge as intercalations in both units [37].

3.3

Conclusions

The Black Sea’s hydrographic network, coastline depths, and seafloor relief are topics of utmost importance in the study of its today morphohydrography and morphodynamics. The hydrographic network of the Black Sea basin stretches on a large surface of Eurasia, 22 countries, of over 22 million km2. From the sea bottom’s characteristics standpoint, the Black Sea is divided into two areas: the North area, characterized by small depths of up to 200 m (especially in the north-western sector), and the South area with great depths (over 200 m, respectively). The continental shelf stretches to depths of 200 m, afterward, the slope of the submarine bottom is abrupt, except for the north-western sector. The biggest depths are in the central area of the sea. In this part, the sea bottom is very pleated, especially to the southern and eastern mountainside, where a series of extinct volcanic cones have been discovered. The Black Sea is a deep basin with steep slopes. The isobath of 100 m is almost entirely parallel to the seashore at a distance of 1.5–6 nautical miles, almost everywhere. Only in the west and north-west and at the entrance into the Kerch Strait this isobath exceeds 20–50 nautical miles from the seashore. In the western basin, between Cape Emine and Cape Yevpatoriya, the 100 m isobath is almost linear (from this to the shore the depths gradually decrease). The isobaths of 200 m, 500 m, and 1000 m are passing by the 100 m isobath, keeping a close configuration to it. The lowest depths of the sea bottom are in the north-western part, and the biggest ones are in the central part of the sea (2000–2200 m, with the biggest depth of 2212 m, having the coordinates: 43 170 N lat., 33 280 E long. Due to the diversity of its surrounding terrestrial relief, the Black Sea accommodates many canyons with multiple aspects. The wide-shelf canyons, typical for the

3.3 Conclusions

91

northwestern and northern Black Sea zone, are associated with large European rivers (Danube, Dniepr, Don, and Kuban). In lowland conditions, these rivers discharged large amounts of clastic material into the Black Sea basin. In the eastern, Caucasian Black Sea, the narrow-shelf canyons developed. These high-energy canyons have been able to transport sedimentary material with various grain sizes, including gravels, as evidenced by the presence of gravel waves. The Black Sea coastlines have a small sinuosity coefficient, with an extremely varied aspect. The forming of the coasts is the result of tectonic factors, sea level variation, sediments’ contribution and character, wave’s conditions, tide, vegetation, etc. Generally, these represent narrow areas, being transformed through the actions of the marine, earthly, and atmospheric processes. The Black Sea coasts are classified into three morphodynamic categories: low coasts, high coasts with seafronts, and mountainous coast. The first complete picture of the paleoenvironments determining the current grain size composition in the Upper and Middle Holocene sediment sections shows that the deposits were accumulated in rather variable lithodynamic conditions. Processes of redeposition have played an important role. At some stages “zero sedimentation” dominated while during other periods scanty terrigenous material was accumulated [37]. In recent years, important projects have been carried out on the Romanian Black Sea coast to restore eroded beaches. The sanding of the beach located in the north of the Mamaia seaside resort is currently underway (Figs. 3.21 and 3.22).

Fig. 3.21 Constanţa beach, April 2018. (Author’s photo)

92

3 The Morphohydrography and Morphodynamics of the Black Sea

Fig. 3.22 Mamaia North beach, February 2021. (Author’s photo)

References 1. ***The Black Sea in the Romanian littoral’s zone. Hydrological Monograph, Bucharest, 1973 2. Panin N, Jipa D (1998) Danube River sediment input and its interaction with the North-Western Black Sea: results of EROS-21 projects. Geo-Eco-Marina 3, Bucharest-Constantza 3. Nicolaev S, Bologa AS (2006) Romanian Involvement in the Black Sea management—scientific and political tools (1990–2005): the case study of The National Institute for Marine Research and Development “Grigore Antipa” 4. Popescu I et al (2015) Submarine canyons of the Black Sea basin with a focus on the Danube Canyon, Submarine Canyon Dynamics—Sorrento, Italy, 15–18 April 2015. CIESM Workshop Monographs no 47 5. Vespremeanu E, Golumbeanu M (2018) Black Sea—physical, environmental and historical perspectives. Springer Geography, Springer International Publishing AG 6. ***Cartea Pilot a Mării Negre, Editura Ex Ponto, Constanţa, (in Romanian), 2006 7. ***Admiralty Sailing Directions, the Black Sea and Azov Sea Pilot. UK Hydrographic Office, NP 24, 6th Edition, London, 2019 8. Sozanski VI (1998) Gaseous regime of the Black Sea. Geo-Eco-Marine 3, Bucharest— Constanţa 9. ***Romania’s geography I. Physical geography. Romanian Academy Publishing House, 1983 10. Kara B et al (2005) Black Sea mixed layer sensitivity to various wind and thermal forcing products on climatological time scales. J Clim 18 11. ***http://emodnet.eu/2017 12. Lericolais G et al (2009) High-frequency sea-level fluctuations recorded in the Black Sea since the LGM. http://intranet.geoecomar.ro/rchm/wp-content/uploads/downloads/2014/11/ Lericolais-et-al_High-frequency-sea-level-fluctuations-in-the-Black-Sea.pdf 13. Panin N, Nicolaev S (2002) Coastal erosion in the Black Sea. The experience of Black Sea environmental programme, suitable coastal management: a Transatlantic and EuroMediterranean perspective, Holland

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14. Panin N et al (1977) Bathymetric research on the Black Sea continental platform. Stud Res Geol Geophys 15 15. Shuisky YD (1993) The general characteristic of the Black Sea, Coastlines of the Black Sea. New York 16. Jipa DC et al (2020) Black Sea submarine valleys—patterns, systems, networks. GEO ECO Marina 26 17. Miladinova S et al (2016) Technical report of the Joint Research Centre (JRC), the European Commission’s science and knowledge service. Changes in the Black Sea physical properties and their effect on the ecosystem. http://publications.europa.eu/resource/cellar/88fd2c79-7e1c4c60-8930-a28cbbb0e91c.0001.02/DOC_1 18. Goryachkin YN (2013) Ukraine. In: Pranzani E, Williams A (eds) Coastal erosion and protection in Europe. Earthscan from Routledge 19. Stănică A et al (2013) Romania. In: Pranzani E, Williams A (eds) Coastal erosion and protection in Europe. Earthscan from Routledge 20. Breier A (1976) Lakes on the Romanian littoral of the Black Sea. Romanian Academy Publishing House, Bucharest 21. Şelariu O (1975) Morphohydrographical observations in the continental platform from the Black Sea’s western basin. Studies, Geol., geophysical research, XVII, Bucharest 22. Şelariu O (1977) Marine researches at the Black Sea. I.M.M.B. Publishing House, Constanţa 23. Charlie RH (2000) The shrinking playground. Using today’s scientific knowledge for the Black Sea area’s development tomorrow. IOI, Black Sea Operational Centre, Constantza 24. Gâştescu P, Driga B (2012) Morphological changes of the Romanian Black Sea accumulation coast. http://limnology.ro/water2012/Proceedings/058.pdf 25. Bondar C, Iordache G (2016) Sediment transport on the Romanian section of the Danube River. https://www.geoecomar.ro/website/publicatii/Nr.22-2016/02_BONDAR_2016.pdf. GEO ECO Marina 22 26. Postolache I, Diaconeasa D (1995) Geomorphological and physical aspects of Romanian coasts. Assessment of coastal change, Conference regarding coastal change, Bordeaux 27. Giosan L et al (1997) Longshore sediment transport pattern along Romanian Danube Delta Coast. GEO ECO Marina 2:11–24. Bucharest 28. Stănică A et al (2007) Coastal changes at the Sulina mouth of the Danube River as a result of human activities. http://intranet.geoecomar.ro/rchm/wp-content/uploads/downloads/2014/11/ stanica_dan_ungureanu_marpolbull_2007.pdf 29. Stancheva M (2013) Bulgaria. In: Pranzani E, Williams A (eds) Coastal erosion and protection in Europe. Earthscan from Routledge 30. Muratov MC (1961) Quaternary history of the Black Sea basin and its comparing with the Mediterranean Sea history. Rev. geography-geology 31. Bologa AS (1998) Regional research and management development in the Black Sea. Cercetări Marine Marine Research 31, I.R.C.M. Constantza 32. Bauchidze IM (1974) Black Sea shelves and littoral zone. The Black Sea geology, chemistry, and biology. Memoire 20. American Association of Petroleum Geologists, Tulsa, Oklahoma, USA 33. Corvin I, Papiu V (1957) Actual marine sediments. Bucharest 34. Gavrilescu N et al (1964) Oceanology researches in the continental platform region, nearby the Romanian coasts. Hydrobiology, I, Bucharest 35. Kosyan R et al (2013) Russian coasts of European seas. In: Pranzani E, Williams A (eds) Coastal erosion and protection in Europe. Earthscan from Routledge, Oxford 36. Yanko-Hombach V et al (2017) Chapter 16: geological and geomorphological factors and marine conditions of the Azov-Black Sea Basin and coastal characteristics as they determine prospecting for seabed prehistoric sites on the continental shelf. In: Flemming NC, Harff J, Moura D, Burgess A, Bailey GN (eds) Submerged landscapes of the European continental shelf: quaternary paleoenvironments. Wiley, pp 431–478 37. Oaie G et al (2005) Black Sea basin: sediment types and distribution sedimentation processes. https://www.researchgate.net/publication/237436023_Black_Sea_Ba-sin_Sediment_Types_ and_Distribution_Sedimentation_Processes. Accessed 17 Jan 2021

Chapter 4

The Influence of the Coastal Relief on the Navigation and Seaborne Trade in the Black Sea

Abstract The Black Sea, considered a Mediterranean sea of the Atlantic Ocean, represents a deep water basin, oriented from west to east, between Europe and Asia Minor, not having very big dimensions (length of around 610–620 nautical miles, and width of 330 nautical miles, with a value of approximately 140 nautical miles in the lowest, narrow part). Although the Black Sea is considered a semi-closed sea, it has performed the connection to the north direction via the Azov Sea through the Kerch Strait, and to the south via the Mediterranean Sea through the Bosporus and Dardanelles straits, and from there with the World Ocean, as well. The coasts of the Black Sea are characterized by a significant diversity, from high costs, as a result of the mountainous chains’ presence near the sea (in the eastern and southern parts), to low coasts, as a result of the presence of some mildly sinuous plains or sand accumulations (in the western and north-western parts), respectively. Keywords Black Sea · Navigation · Coastal relief The analysis of the environment’s influence as regards the navigation and the seaborne trade on the Black Sea implies knowledge of how the main factors of the marine environment determine favorable or unfavorable conditions for the ship’s displacement, respectively, on the coastal routes or in the open sea, during winter or the warm seasons, in favorable weather or on a rough sea. The Black Sea is an open sea for navigation during the entire year because of its geographical position, which determines the zone’s climate (namely, it is situated north of parallel 44
N, meaning it has a temperate climate, and south of parallel 44
N, meaning it has a subtropical climate). The characteristics of these two types of climate, respectively, are relatively mild and wet winters and warm and arid summers for the temperate climate and warm winters and relatively dry, warm, and rainy summers [1] for the subtropical climate. All the factors mentioned above make navigation in the area propitious. The shape and height of the coasts have the following influence on navigation: the coast that is predominantly high in the south and east parts ensures an excellent visual and radar orientation and installation of aids for navigation is very easy (i.e., lighthouses, specialized light, and unlit coastal landmarks); the coast that is © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_4

95

96

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

predominantly lower in the northwestern part of the Black Sea is unfavorable to orientation and, in conjunction with the fact that small depths are advancing far into the open sea, navigation is conducted at relatively large distances from the coast (and cautiously near the coast, as well). Capes are very important for sea orientation, the most visible being Tarhankut, Chersones, Sarici, Meganom, and Doob in the northern part of the Black Sea; Pitsunda in the east; Chiam, Indjeburun, and Baba in the south; and Emine, Kaliakra, and Tuzla in the western part of the Black Sea [2]. In case of a storm, in the Black Sea, there are only a few natural zones for taking refuge and almost all gulfs and bays are exposed to open sea winds (e.g., Karkinit and Kalamit bays; Feodosia and Taman in the north; Novorossiysk on the eastern coast; Sinope, Samsun, and Eregli in the south; and Burgas and Varna on the western coast). The presence of the Crimean peninsula stands out; as it modifies the coastline, it creates bays and represents a special natural landmark for navigation. The Black Sea is a deep basin; therefore, the navigation of large vessels becomes possible near the coast, as well as that of submarines in case of immersion. The favorable coasts and the maritime ports afferent to them ensure the development of navigation and shipping along the entire sea. The propitious physical-geographical conditions, that ensure refuge for the ships against the winds and storms (gulfs and bays) have determined the ports’ apparition on the Black Sea coast, as follows: in gulfs and bays, Burgas, Varna, Odesa, Suhumi, Trabzon, Samsun, Zonguldak ports, etc. (i.e., in the bays with the same names); in bays sheltered by capes or higher coasts: Mangalia, Constanţa, Midia, Novorossiysk, Batumi, Sinope, Eregli, etc. The shape and dimensions of the Black Sea determine the length and orientation of the maritime routes (the recommended routes, respectively) between the ports of the Black Sea; thus, these alternate between 50 and 600 nautical miles, with orientation on the whole horizon, most of them in a straight line. This means that for a medium speed of 12–14 knots, the transport routes of the Black Sea can be covered in a relatively small period, respectively 4–50 h (Fig. 4.1). Making a comparison, the routes of the Black Sea are covered by merchant ships in tens of hours and days and the oceanic ones in days and weeks [2]. Moreover, the dominant influence of the Black Sea’s connections with Sea of Azov and the Mediterranean Sea must be emphasized as regards the shipping. The Black Sea has a connection with the Sea of Azov through the Kerch Strait, ensuring commercial connection with an area rich in resources, with the Mediterranean Sea through the Bosporus and Dardanelles straits, and ensuring connection with the World Ocean. In conclusion, we can state that the Black Sea is the most eastern Mediterranean sea of the Atlantic Ocean, and its basin is an integral part of the economic zone of the South–East and South of Europe. For maritime navigation, the knowledge of the maritime zones’ magnetic characteristics is fundamental to diminish the influence of terrestrial magnetism on the magnetic compass and of the magnetic storms on the functioning of navigation equipment. Generally, the magnetism of the Black Sea is little known (especially in

4.1 The Black Sea Coast’s Lights

97

Fig. 4.1 Source: public picture from Marine Vessel Traffic, Black Sea Ship Traffic Live Map, https://www.marinevesseltraffic.com/BLACK-SEA/ship-traffic-tracker?map¼vf [5]

the Black Sea southern sector). The magnetic declination, which is the plane angle between the true north direction and the compass direction (i.e., the direction at the Magnetic North), has a positive value (east) in the south-eastern part of the sea and a negative value (west) in the south-west; its value is changing quite uniformly. The isogonic lines, which are lines of equable magnetic declination, have the aspect of straight lines in the north-west direction. The secular variation of the magnetic declination or magnetic variation is not very big, this fact allowing the use of the same magnetic corrections for many years [3] (Table 4.1). According to the data presented by the Marine Vessel Traffic.com, the map of the sea traffic in the Black Sea looks as shown in Fig. 4.1 [4]. One can see the main routes from the Bosporus to the ports on the western façade of the Black Sea (Constanţa, Varna, Burgas, Odesa, Sulina), but also to the Sea of Azov and the port of Novorosiysk. The known regions of the Black Sea having magnetic anomalies are Gulf of Odesa, Gulf of Burgas, and from the port of Tuapse to the port of Batumi; the magnetic storms have been reported in the years with maximum solar activity when the amplitude of the magnetic declination oscillations can reach 1.3 degrees [5].

4.1

The Black Sea Coast’s Lights

On the Black Sea coast, there are 62 main lighthouses, to which are added numerous lights and special lights for ports entrances, various hydro-technical constructions, and navigation dangers (Table 4.2 and Fig. 4.2) [6]. The Romanian coast of the Black Sea has an approximative north-south orientation, except for the Midia–Sfîntu Gheorghe zone, with extreme points, respectively

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

98

Table 4.1 Distances between the Black Sea’s main ports [1] BATUMI BURGAS VARNA KERCH CONSTANTA

SINOPE ISTANBUL SUKHUMI TRABZON TUAPSE FEODOSIA KERSON YALTA

255

188

318

372

80

125

594

402

320

364

632

429

399

80

440

472

249

360

81

170

333

246

290

563 30 412

NOVOROSIYK

POTI SEVASTOPOL

618

444

245

MYKOLAIV

ODESSA

408

632

57

399

550 165

228 211

619 234

586 208

296 182

606 257

672 291

191

292

337

203

406

325

210

333

347

293

310

298

579

344

455

416

192

432

147

126

589 84

557

270

357

57

508

177

577

544

247

575

597

131

516

218

360

110

512

236

553

528

295

540

559

93

113

483

212

262

162

412

69

481

450

142

486

514

186

168

307

273

377

186

117

318

270

110

339

309

72

355

385

338

320

462

565

563

412

379

211

600

86

413

60

240

376

312

362

612

66

212

323

311

314

157

54

353

206

161

243

242

129

284

317

368

in the south, Vama Veche, and in the north, Starâi Stambul (Gârla Musura), branch, representing the southern branch of the Chilia Delta. A general characteristic of the coast is its small grade of sinuosity, with few capes (Cape Tuzla, Cape Singol, Cape Midia), and small bays (Mamaia Bay, Gura Portiţei Bay). This zone, having relatively small sinuosities from Danube’s branches Sulina and Sfântu Gheorghe, cannot ensure the ships’ shelter and refuge in case of navigation under unfavorable conditions. Another characteristic is coast visibility: the southern zone is visible from the sea from relatively large distances (e.g., a coast with terraces, respectively of 2–40 m, is visible from distances of more than 10 nautical miles), but in the zone from north of Cape Midia to Sulina, the coast is hardly visible, even if navigation is performed nearby (as a result of the fact that the coast is low in this area (Fig. 4.3), it is no longer visible from a distance larger than three nautical miles) [7]. In the northern zone, between Cape Midia and Sfîntu Gheorghe Mouth, there is only one lighthouse, Gura Portiţei Lighthouse (height 22 m); 10 nautical miles visibility; and two unlit signals (Chituc and Zaton); therefore, the visual orientation in the respective zone is precarious; therefore, between Chituc and Zaton, coastal navigation cannot be performed in safety conditions at distances longer than 5–10 nautical miles from the coast (i.e., in the respective area, there is no coastal landmark). In Sfântu Gheorghe–Sulina sector, there are two maritime lighthouses placed as follows: one of them at Sfântu Gheorghe (height 48 m, 19 nautical miles visibility), and the second one at Sulina (height 49 m, 19 nautical miles visibility) [6], ensuring favorable conditions for the achievement of coastal navigation at a distance between 5 and 15 nautical miles from the coast (Fig. 4.4).

E 5107 E 5108 E 5278

Romania E 5018 E 5022 E 5025 E 5030 E 5031 E 5032 E 5034 Ukraine E 5078 E 5106

Code

Tarkhankutskiy Cape

Sychavskyi

Severniy Odesskiy Cape (Luzanovskiy) Grigor’evskiy

Odesskiy

Sulina

Sfântu Gheorghe

Gura Portiţei

Midia

Constanţa

Tuzla

Mangalia

Name

46 35,96 31 00,04 46 37,03 31 07,20 45 20,82 32 29,60

46 22,64 30 44,84 46 33,12 30 49,60

43 48,65 28 33,52 43 59,45 28 39,98 44 09,49 28 37,83 44 20,84 28 40,98 44 40,53 28 59,24 44 53,95 29 36,02 45 08,90 29 45,55

Lat. Long. (. . .0 . . .’)

Table 4.2 Black Sea main lights [6]

Fl (2) W 7,5 s

Fl W 4 s 36

44

60

56

Fl W 5 s

Fl W 3 s

84

49

48

22

36

87

62

72

Height of light (m)

Fl (3) W 12 s

Fl (3) W 16,2 s RACON

Fl (2) W 7,2 s

Fl W 9 s

Fl W 5 s

Fl (2) W 29,8 s

Fl (2) W 9,7 s

Fl (2) W 5,5 s

Characteristics of light

17

15

18

16

22

19

19

10

17

24

20

22

Visibility (M)

33

10

15

10

42

48

50

23

22

58

44

42

Height of construction (m)

1,5 + (1,5) + 1,5 + (3,0) W 287
– 168
(241
)

1,5 + (3,5)

0,5 + (2,5) Vis. 272
– 060
(148
)

1,5 + (3,5)

(continued)

1,5 + (1,5) + 1,5 ++ (1,5) + 1,5 + (4,5) Vis. 197
– 047
(210
) 0,5 + (4,5)

0,4 + (1,5) + 0,4 + (1,5) + 0,4 + (12,0) Vis.165
– 045
(240
)

0,1 + (1,7) + 0,1 + (5,3)

1,0 + (8,0)

1,5 + (3,5)

0,4 + (6,6) + 0,4 ++ (22,4)

0,2 + (2,3) + 0,2 + (7,0) Vis. 191
– 14
(183
)

0,1 + (1,3) + 0,1 + (4,0)

Period of light

4.1 The Black Sea Coast’s Lights 99

Name

E Yevpatoriyskiy 5282 Cape E Lukull’skiy 5288 Cape E Khersonesskiy 5308 Cape E Fiolent cape 5309 E Ay – Todorskiy 5316 Cape E Meganom Cape 5330 (Mehanom) E Chaudinskiy 5352 Cape Russian Federation E Akhilleonskiy 5428 Cape E Anapskiy Cape 5618 E Doobskiy 5636 E Novorossiysk 5642.1 Port E Tolstyi Cape 5656 E Gelendzhik 5658

Code

Table 4.2 (continued)

45 26,44 36 47,21 44 53,27 37 17,94 44 37,63 37 54,62 44 44,70 37 47,11 44 33,01 38 03,00 44 34,46 38 04,08

45 09,06 33 16,14 44 49,98 33 33,40 44 35,00 33 22,73 44 30,03 33 29,28 44 25,69 34 07,32 44 47,78 35 04,83 45 00,27 35 50,21

Lat. Long. (. . .0 . . .’)

100 74 62 17

Fl (3) W 16.5 s

Oc Y 6 s

Fl.(2) W 15 s

F RY

37

Fl L W 24 s

43

99

Fl (3) W 14 s

Fl L(2) R 15 s

87

Fl (2) G 6 s

63

12

168

Izo R 6 s

16

34

Mo(SW) W 60 s Fl R 3 s

9

21

16

21

17

17

17

25

24

16

41

Fl W 3 s

20

Visibility (M)

53

Height of light (m)

Fl (2) W 10 s

Characteristics of light

13

42

14

23

21

20

16

12

9

4

36

16

52

Height of construction (m)

R 038
5 – 044
8 (63
) Y 044
8 – 051
5 (6,7
) R 051
5 – 057
5 (6
)

0,5 + (3,2) + 0,5 + (10,8) W 321
– 220
(259
)

4,5 + (1,5) Vis. 12,5


W 325
– 152
(187
)

3,0 + (3,0) + 3,0 ++ (6,0)

6,0 + (18,0)

1,0 + (1,0) + 1,0 + (1,0) + 1,0 + (9,0). W 289
– 058
(129
)

0,2 + (1,3) + 0,2 + (4,3) G 232
– 071
(199
)

3,0 + (3,0) + 3,0 + (3,0) + 3,0 + (6,0) + 3,0 + 3,0 + (6,0) + 3,0 + (6,0) + (18,0) 3 + (2) + 6 + (4) 0,5 + (2,5) R 282
– 148
(226
)

0,3 + (2,7)

0,2 + (2,4) + 0,2 + (7,2) W.247,5
– 123,8
(236,3
)

Period of light

100 4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

E 5668 E 5684 E 5686 E 5698 Georgia E 5706 E 5718 E 5721 E 5726 E 5747 E 5765 E 5768 Turkey E 5780 E 5782 E 5784 E 5786

43 19,74 40 12,85 43 08,95 40 20,31 43 05,64 40 36,48 42 58,92 40 58,24 42 16,41 41 38,15 41 51,10 41 46,70 41 39,35 41 38,47

41 22,34 41 22,66 41 02,39 40 30,32 41 00,52 39 44,10 41 06,28 39 25,12

Gagrinska Reyd.

Çamli Burnu

Trabzon Güselsihar Cape Işikli Cape (Yeros)

Rize Cape

Batumi Port

Kobuleti

Kulevi

Sukhumi Cape

Bambora

Pitsunda Cape

Adlerskiy

Sochinskiy

44 05,89 39 02,19 43 54,18 39 20,63 43 34,74 39 43,21 43 25,48 39 54,91

Kodoshskiy Cape Lazarevskiy

31 25

Fl W 10s

22

23

20

37

37

38

36

87

Fl (2) W 15 s

Fl W 5 s

Fl (2) W 15 s

Fl (2) R 6 s

FL G 3 s

Oc (4 + 1) W

Fl L(2) W 15 s

Fl W 3 s

Fl (2) W 10,2 s

Fl (2) W 5 s

Fl (2) Y 8 s

37

110

Fl W 6 s

Izo Y 3 s

62

Fl (3) W 14,2 s

18

17

18

19

14

15

16

17

16

19

18

13

20

20

21

8

6

18

12

20

30

45

34

35

31

21

12

15

15

14

0,4 + (9,6)

1,0 + (2,0) + 1,0 + (11,0)

0,5 + (4,5)

0,4 + (4,6) + 0,4 + (9,6)

0,2 + (1,3) + 0,2 + (4,3)R 065
– 310
(245
)

0,5 + (2,5) G 018
– 185
(167
)

3,0 + (3,0) + 3,0 + (6,0)W 236
,7 – 115
,7 (239
)

1,0 + (2,0) W 275
– 085
(170
)

0,2 + (2,1) + 0,2 + (7,7) W 269
– 150
(241
)

1,0 + (1,0) + 1,0 + (2,0) W 341
– 105
(124
)

1,0 + (2,0) + 1,0 + (4,0) Y 330
– 130
(160
)

Y 296
– 161
(225
)

1,5 + (4,5) W 323
– 130
(167
)

0,4 + (2,5) + 0,4 + (2,5) + 0,4 + (8,0) W 313
– 129
(176
)

(continued)

4.1 The Black Sea Coast’s Lights 101

Tirebolu Kale Cape Giresun

E 5788 E 5790 E 5794 E 5806 E 5810 E 5816 E 5817 E 5820 E 5826 E 5832 E 4964 E 4966

Rumeli Karaburun Koru Cape

Ereğli Olüce Cape Şile Cape

Zonguldak Cape

Amasra

Kerempe Cape

Ince Burun

Bafra cape

Çam Cape

Name

Code

Table 4.2 (continued)

41 00,48 38 49,26 40 55,38 38 23,41 41 06,98 37 47,18 41 43,85 35 56,80 42 05,90 34 56,70 42 01,02 33 20,24 41 45,16 32 22,97 41 27,88 31 47,25 41 18,80 31 23,96 41 10,68 29 36,98 41 20,88 28 40,97 41 53,09 28 03,34

Lat. Long. (. . .0 . . .’)

54 44

Fl (2) W 15 s

60

Fl W 15 s

Fl W 5 s

78

53

77

82

26

25

Fl (2) W 10s

Fl W 5 s

Fl W 10s

Fl W 20s

Fl (4) W 20s

Fl W 5 s

39

111

Fl W 15 s

Fl W 10s

31

Height of light (m)

Fl R 4 s

Characteristics of light

20

15

21

15

20

20

20

18

20

18

18

18

Visibility (M)

8

12

19

9

9

4

8

12

25

8

12

Height of construction (m) Period of light

0,3 + (4,7) + 0,3 + (9,7)

0,5 + (4,5)

1,5 + (13,5)

0,5 + (2,0) + 0,5 + (7,0)

0,5 + (4,5)

1,0 + (9,0)

1 + (1) + 1 + (1) + 2,5 ++ (25,5)

0,5 + (2,0) + 0,5 + (2,0) + 0,5 + (2,0) + 0,5 ++ (12,0)

0,5 + (4,5)

1,0 + (9,0)

1,5 + (13,5)

1,0 + (3,0)

102 4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Bulgaria E Maslem Nos 4974 Zeitin Cape E Sveti Ivan 4976 E Emine Eminski 4996 Cape E Galata Cape 5000 E Kaliakrenski 5012 E Shablenski 5016 Bosphorus Strait E Türkeli Feneri 4956 E Anadolu Feneri 4958

41 14,07 29 06,72 41 13,04 29 09,13

42 18,50 27 47,70 42 26,30 27 41,50 42 42,10 27 54,10 43 10,20 27 56,80 43 21,80 28 28,00 43 32,40 28 36,50 68 36

Fl W 5 s

Fl (3) W 20 s

75

76

Fl (3) W 15 s

Fl L W 20 s

64

Fl W 6 s

58

44

Fl (2) W 10 s

Fl (2) W 12 s

37

Fl (3) W 17,2 s

20

18

17

21

26

20

18

17

20

30

32

10

22

9

13

7

2,0 + (18,0)

1,0 + (3,0) + 1,0 + (7,0)

0,5 + (0,5) + 0,5 + (2,5) + 1,0 + (15,0)

0,5 + (4,5)

0,5 + (1,5) + 0,5 + (2,0) + 0,5 + (10,0)

1,5 + (4,5)

0,5 + (2,0) + 0,5 + (7,0)

0,4 + (4,0) + 0,4 + (4,0) + 0,4 + (8,0)

(continued)

4.1 The Black Sea Coast’s Lights 103

Legend

Code

Name

Table 4.2 (continued)

Lat. Long. (. . .0 . . .’)

Fl Oc Izo F L W R G Y vis

1

2

3

4

5

6

7

8

9

19

Visibility (M)

Abbreviation

Height of light (m)

No.

Characteristics of light

Height of construction (m)

visibility

yellow

green

red

white

long

fix

isoohase

occultations

flash

Signification

Period of light

104 4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

4.1 The Black Sea Coast’s Lights

105

Fig. 4.2 Black Sea’s main lighthouses

Fig. 4.3 Gura Portiţei beach. (Author’s photo)

Taking into consideration the hydrographical factor, the characteristics are as follows: in the southern part, from Mangalia to Constanţa south, an isobath of 10 m passes at a distance of about 0.8–1.0 nautical mile and an isobath of 20 m at about two nautical miles from the coast (having a closeness of one mile in the zone of Cape Tuzla), allowing, thus, coastal navigation without difficulty; in the northern part, the small depths are advancing far into the sea, making navigation near the coast

106

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Fig. 4.4 Gura Portiţei Lighthouse; Sfântu Gheorghe Lighthouse; Sulina Lighthouse. (Author’s photos)

dangerous, even for small ships; from Cape Clisargic to Gura Portiţei, an isobath of 5 m passes at a distance of 0.3–0.6 m from the coast, and further to the north of Gura Portiţei, this isobath is moving further away from the coast; therefore, in the south of Sahalin island, an isobath of 10 m passes at a distance of 1.5 nautical miles (an isobath of 20 m passes at a distance of 3.5 nautical miles in the south of Sulina’s mouth, in the south of Sahalin Island, and between Sfântu Gheorghe’s mouth and Sulina, at approximately one mile, respectively) [8–12]. In Romanian ports’ entry zones, the sea depth is as follows: in Mangalia, between 10 and 20 m (Mangalia roadsted has depths between 15 and 25 m); in Constanţa, between 20 and 50 m (Constanţa roadstead has depths of over 25 m), in Midia, between 10 and 15 m (Midia roadstead has depths of over 10 m), in Sulina, between 10 and 20 m. The coast of the southern zone of the Romanian littoral is relatively high (Figs. 4.5 and 4.6), therefore making possible the installation of some lighthouses, visible on the sea from different distances: 22 nautical miles Mangalia Light (height 72 m), 20 nautical miles Tuzla Light (height 62 m), 24 nautical miles Constanţa Light (height 87 m), 17 nautical miles Midia Lighthouse (height 36 m); hence, the maritime zone, having the width of 20 nautical miles between Mangalia and Midia, is covered by two or three lighthouses, and coastal navigation can be performed in good conditions (Fig. 4.7). On the Bulgarian Black Sea coast, the main lighthouses are positioned at favorable heights, which ensures them very good visibility. In the northern part, the Bulgarian coast is high with cliffs (Fig. 4.8), and in its southern part, there are capes visible from the sea, from a great distance [8, 11, 13]. The main Bulgarian lighthouses are positioned as follows: Shabla Lighthouse (light height 36 m), Kaliakra Lighthouse (light height 68 m), the lighthouse on

4.1 The Black Sea Coast’s Lights

107

Fig. 4.5 South Tuzla Cape’s terrase. (Author’s photo)

Fig. 4.6 Vama Veche terrase. (Author’s photo)

Galata Cape (light height 76 m), and the one on Emine Cape (light height 64 m) (Figs. 4.9 and 4.10) [13, 14]. At the entrance of Bosporus Strait, from the Black Sea, sailors use for orientation two famous lighthouses (Fig. 4.11), located on high places with good visibility: Türkeli Feneri (Turkey’s tallest lighthouse, on the west side of the entrance) and Anadolu Feneri (on the east side of the entrance) [14, 15].

108

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Fig. 4.7 Constanţa Lighthouse; Tuzla Lighthouse; Mangalia Lighthouse. (Author’s photos)

Fig. 4.8 North Bulgarian coast at Yailata. (Author’s photo)

On the southern Turkish coast of the Black Sea, the main lighthouses are the ones positioned on the important capes in this area: Şile, Amasra, Zonguldak, Kerempe, and Bafra (Fig. 4.12) [16–18]. On the Georgian coast, the main lighthouses are Gagrinskiy, Pitsunda, Sukhumi, Batumi, and Poti (Fig. 4.13) [19, 20].

Fig. 4.9 Shablensky Lighthouse. (Author’s photo). Kaliakrenski Lighthouse. (Source: Spiridon Manoliu, public domain, the credit under Creative Commons licenses)

Fig. 4.10 Galata Cape. (Source: Svilen Enev, public domain, the credit under Creative Commons licenses). Eminski Cape Lighthouse. (Source: Evgeny Dinev, public domain, the credit under Creative Commons licenses)

Fig. 4.11 Türkeli Feneri (Rumeli Lighthouse). Anadolu Feneri. (Source: Alexander Trabas Webmaster Online List of Lights, www.ListofLights.org, By courtesy of Captain P. Mosselberger)

110

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Fig. 4.12 Şile Cape Lighthouse. Amasra Cape Lighthouse. (Source: By courtesy of A. Trabas, Webmaster Online List of Lights, www.ListofLights.org)

Zonguldak Lighthouse. Bafra Lighthouse. (Source: By courtesy of A. Trabas Webmaster Online List of Lights, www.ListofLights.org)

On the coast of the Russian Federation, the main lighthouses are Doobsky, Gelendzhik, Anapa, Novorossiysk, and Sochinskiy (Fig. 4.14) [21–26].

4.1 The Black Sea Coast’s Lights

111

Fig. 4.13 Batumi Lighthouse; Pitsunda Lighthouse, Poti Lighthouse (Source: Public pictures from https://www.ibiblio.org/lighthouse/geo.htm; http://hydrography.ge/en/photo_gallery.php)

Fig. 4.14 Doobsky Lighthouse; Gelendzhik Lighthouse; Anapa Lighthouse

112

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Sochi Lighthouse of north mole Novorossiysk Light (Vostochhniy Mole, East Mole). (Source: Public pictures from https://www.lightphotos.net/photos/thumbnails.php?album¼211)

Fig. 4.15 Entrance Dnieper River /Stanislaus–Adzhyholskyy Odesa Lighthouse /Vorontsov Lighthouse. (Source: Free pictures https://www.lightphotos.net/photos/thumbnails.php?album¼40 [27, 28])

On the coast of Ukraine, the main lighthouses are: Odeskiy, Yevpatoriyskiy, Khersonesskiy, Ay-Todorskiy, and Meganom (Fig. 4.15).

4.2

Conclusions

The Black Sea, considered a Mediterranean sea of the Atlantic Ocean, represents a deep water basin, oriented from west to east, between Europe and Asia Minor, not having very big dimensions (length of 610–620 nautical miles and width of 330 nautical miles, with a value of approximately 140 nautical miles in the lowest, narrow

4.2 Conclusions

113

part). Although the Black Sea is considered a semi-closed sea, it has performed the connection to the north direction via the Sea of Azov through the Kerch Strait, and to the south via the Mediterranean Sea through the Bosporus and Dardanelles straits, and from there with the World Ocean, as well. The coasts of the Black Sea are characterized by a significant diversity, from high coasts, as a result of the mountainous chains’ presence near the sea (in the eastern and southern parts), to low coasts, as a result of the presence of some mildly sinuous plains or sand accumulations (in the western and north-western parts). On the Black Sea coast, there are some regions without any kind of vegetation, close to portions cove-red by subtropical and temperate vegetation. A characteristic of the coasts is their permanent modification, as a result of the currents’ and waves’ action, causing the coast’s destruction and the uniformity of its lines in some areas. In other areas, the production of deposits’ accumulation results in new land portions and causes the modification of the depth and the sea bottom’s relief, as well. The strong erosion has an important influence for the capes and recesses of the Black Sea coast. The coasts’ erosion and withdrawal process is less visible in the area of the large rivers’ and rivers’ mouths, having a strong silt flow (e.g., the Danube, the Dnieper, the Inguri and the Rioni); during the flood periods, significant increases in solid matters’ sediments can be observed. The Romanian littoral’s coasts have a distinctive characteristic: the southern part consists of the western slope of Dobrogea’s plateau, and it has the shape of a mildly inclined plain from south to north, with reduced decomposition and abrupt margins towards the sea. The largest part of this plateau is used for agriculture. In the northern part, the Danube Delta (the biggest in Europe and the third worldwide in size) presents particular aspects, i.e., it is low and almost without forests, with small wooded portions on the banks of Sfîntu Gheorghe’s branch. The Black Sea coasts are a little jagged, and they do not have big bays (the biggest is Karkinit Bay, located between the continental part and the north-eastern coast of the Crimean Peninsula). A primary characteristic of the Black Sea is the absence of big islands; in the Black Sea, the biggest island is Serpent Island, located close to the Danube Delta, at a distance of 19 nautical miles from the coast (the depth in the middle of the distance between the coast and Serpent Island is 27.5 m, uninhabited, having a surface of 17 hectares, a high coast of up to 21 m, depths at the coast between 6 and 15 m). Other islands include Sacalin Island, located south of Sfîntu Gheorghe Mouth, and it consists of silts brought by the Danube; Berezan Island, placed at the entrance in Berezan Bay; and Kefken Island, found in the southern part of the Black Sea. Furthermore, the importance of the Crimean Peninsula must be emphasized, with its unique role as regards the geographical, climatic, and hydrographical aspects of the Black Sea basin. The submarine sand waves are forming close to the coasts having small depths; in conclusion, the sand is the prevailing element, but, at depths of 20–30 m, it is replaced by the sandy ooze, and the sea bottom consists of clayey ooze at bigger depths than those previously mentioned. And in the zone with rocky coasts, it is replaced by coquina limestone.

114

4 The Influence of the Coastal Relief on the Navigation and Seaborne Trade in. . .

Taking into consideration the aids to navigation, the physical-geographical conditions (position, dimensions, the coasts’ shape, the depth, etc.) of the Black Sea ensure proper conditions for navigation and seaborne trade, in conditions of safe navigation and good precision, in the coastal zones, but with some exceptions (e.g., along the Romanian littoral – Gura Portiţei Bay sector), and good conditions in the open sea.

References 1. ***Romanian Black Sea Pilot Volumes 1 and 2 with amendments, EX PONTO Publishing House, Constanta (in Romanian), 2006 2. Boşneagu R (2004) Geographical Conditions Influence of the Maritime Routes in the Black Sea Basin (Western sector). Cartea Românească, Publishing House Bucharest, Romania (in Romanian) 3. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 3rd Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2010 4. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 4th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2013 5. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 5th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2017 6. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 6th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2019 7. ***https://www.marinevesseltraffic.com/BLACK-SEA/ship-traffic-tracker?map¼vf,¼a. Accessed 19 July 2020 8. Dogaru P (1996) Serpents Island in the sharks’ way. Vestala Publishing House, Bucharest (in Romanian) 9. ***Cartea farurilor şi semnalelor de ceaţă din Marea Neagră DH 103 (in Romanian) 2014 10. ***https://www.ibiblio.org/lighthouse/rou.htm 11. ***Admiralty List of Lights and fog Signals East Mediterranean and Black Seas NP 86 Volume N, UK Hydrographic Office,Taunton, Somerset, United Kingdom, 2019/20 12. ***Admiralty List of Radio Signals, Maritime Radio Stations Europe, Africa and Asia (excluding the Far East) NP 281 (1) Volume 1, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2019/20 13. ***Admiralty IALA Buoyage System NP 735 8th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2018 14. ***https://www.lightphotos.net/photos/thumbnails.php?album¼211 15. ***http://www.listoflights.org/ 16. ***https://www.vagabond.bg/travel/high-beam/item/1806-bulgarias-lighthouses.html 17. ***http://www.lighthousesrus.org/showSql.php?page¼AM/Bulgaria) 18. ***http://www.lighthousesrus.org/showSql.php?page¼AM/TurkeyN 19. ***https://www.ibiblio.org/lighthouse/geo.htm 20. ***http://hydrography.ge/en/photo_gallery.php 21. ***https://www.lightphotos.net/photos/thumbnails.php?album¼211 22. ***https://www.lightphotos.net/photos/displayimage.php?album¼211&pid¼14126 23. ***https://www.lightphotos.net/photos/displayimage.php?album¼211&pid¼8195 24. ***https://www.lightphotos.net/photos/displayimage.php?album¼211&pid¼2132 25. ***https://www.lightphotos.net/photos/displayimage.php?album¼211&pid¼21896 26. ***https://www.lightphotos.net/photos/displayimage.php?album¼211&pid¼5116 27. ***https://www.lightphotos.net/photos/displayimage.php?album¼light&cat¼0&pid¼9084 28. ***https://www.lightphotos.net/photos/displayimage.php?album¼40&pid¼1746

Chapter 5

The Black Sea Basin’s Meteo-Climatic Characterization

Abstract In the Black Sea coast area, the annual average temperature is between 10 and 15.2
C and the maximum temperatures generally vary within limits 40 to + 40
C. In the Black Sea basin, the annual average pressure is approximately 1016– 1018 Mb, having extreme values in July–August (i.e., 1011–1014 mb), and in January (1018–1025 mb). The pressure distribution at a given moment in the Black Sea area differs very much from the average pressure distribution for that period. There are 14 types of baric fields more frequently acting on the Black Sea, out of which the most important for the winds’ formation over the Black Sea being as follows: the weak gradient, the weak wind (2 m/s), the cyclone in the eastern sea part, the southern edge of the cyclone, the cyclone northern edge, the eastern edge of the cyclone, the eastern edge of the anticyclone, and the southern part of the anticyclone. Keywords Black Sea · Atmospheric pressure and circulation · Wind

5.1 5.1.1

Anemobaric Regime, Atmospheric Circulation, and Wind Regime in the Black Sea Basin Atmospheric Pressure Conditions in the Black Sea Basin

Generally, the atmospheric pressure represents the main element in the meteorological analysis and the anemobaric regime, in particular. The atmospheric pressure regime is analyzed regarding the atmospheric pressure’s variation in time and space, at the sea surface, and in altitude. The isolated values of the atmospheric pressure are important in climatology, in the atmospheric pressure's static analysis for a certain fixed point, but they cannot be taken into consideration in global meteorology, in air masses dynamics, respectively. In synoptic meteorology, the atmospheric pressure regime is analyzed complexly, by reducing it to certain reference levels (the sea surface or other altitude levels). The even distributions of the atmospheric pressure allow the marking of some isobars that determine regimes of various types on a planetary scale, at the level of a © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_5

115

116

5

The Black Sea Basin’s Meteo-Climatic Characterization

continent, of a sea basin, or a certain sea. Concerning the area’s specific conditions, baric regimes with their characteristics can be differentiated. The atmospheric pressure regime also allows the determination of the changing conditions of the atmospheric air—the wind regime. The size of the baric gradient determines wind intensity. For a comparison of the gradients of the sea surface, they can be differen
tiated about the value of an equatorial degree, 1 ec ffi 111 km. Specifically, the anemobaric regime that determines strong winds (14 m/s speed) in the Black Sea basin occurs when in the analysis chart that includes this maritime basin  four isobars are recorded, which corresponds to a gradient of 2.5 Mb/sec. The distribution of the atmospheric pressure on the Earth's surface is uneven because the weight and the air pressure depend on its density, as well as the latitude of the area (the gravitation forces vary with latitude). Under well-known laws of physics, in its turn, the air density depends on temperature, humidity, and atmospheric pressure, as follows: – The higher the air temperature, the more its density is reduced, as with the increase of air temperature, the air expands and its quantity decreases in a volume unit. – The higher the air humidity, the lower the density, as the vapor molecular weight represents only 0.622 of the air molecular weight. – The higher the atmospheric pressure under which there is air volume, the higher its density, as the pressurized gas easily compresses under pressure and it expands by reducing the pressure. The weight of one m3 of dry air is 1293 g/m3, and the pressure is 1033 kg/cm2 under normal conditions for the Black Sea (45
N latitude, 0
C temperature at the sea level). The atmospheric pressure has no particular importance as a singular value at a certain point, but its special significance must be considered taking into consideration its variations in space and time. The atmospheric pressure variation in time allows to determine the baric tendency and, in conjunction with this, the possibility to assess the changes in the baric field. The atmospheric pressure variation in space, in the vertical direction, is essential as regards reducing the pressure to a particular reference level (i.e., at different standard levels of altitude or sea level). From a dynamic meteorology’s point of view, the variations of the atmospheric pressure over time (i.e., diurnal and annual), which have a variable character (periodical), as well as the nonperiodic variations (accidental) and the horizontal barometric gradient variations, are of particular interest. Although the daily variations of the atmospheric pressure do not change the weather conditions, the navigators cannot ignore them, as in the tropical regions they can reach up to 2–3 Mb., and such a pressure drop in a relatively short time could be interpreted as a sign of a tropical storm approaching the ship, but for the middle latitudes of the Black Sea, this situation is less visible. The nonperiodic variations of the atmospheric pressure, depending on a large number of factors are the most unpredictable changes. However, generally, it can be stated that these variations increase with the latitude, but differently, on the sea

5.1 Anemobaric Regime, Atmospheric Circulation, and Wind Regime in the Black. . .

117

compared to the land; the monthly medium amplitudes of these variations for the Black Sea region range between 21–28 Mb (onshore), and between 26–36 Mb (on the sea). The atmospheric pressure is a variable in time and space (in altitude and on the horizontal direction). The atmospheric pressure decreases with height, concerning the reduction of the atmospheric layers’ pressure, but in a complex, nonlinear variation. In connection with this, the concept of the baric step is used, which represents the variation of the height h, for which a pressure variation equal to the unit (i.e., 1 mm Hg or 1 Mb) is realized. The baric step variations depend on temperature and pressure. For the Black Sea coastal area, where the annual average temperature is between 10 and 15.2
C and the maximum temperatures generally vary within limits 40
C to +40
C, the baric step variations are as follows (Table 5.1 and Fig. 5.1): It can, thus, be noticed that when pressure increases, the baric step decreases, and when temperature rises, the baric step also increases. The pressure variation is explained by taking into account the uneven warming of the Earth and also the differentiated absorption and reflection phenomena occurring within the air–land or air–sea contact surfaces. In the Black Sea, the annual average pressure is of approximately 1016–1018 Mb, having extreme values in July–August (i.e. 1011–1014 Mb) and in January (1018–1025 Mb) [1–4]. As a result of the thermophysical properties of the underlying surface (meaning the Earth surface in contact with the atmosphere during the processes of heat exchange and conversion of the solar radiation into caloric energy), there is a phase difference between the atmospheric pressure at the sea and the land level which causes some circulatory disturbances having a local character. Also, the Table 5.1 The baric step variations depending on air temperature and atmospheric pressure for the Black Sea coastal area

Temperature Pressure 1000 Mb 500 Mb 100 Mb

40
C 6.7 13.4 67.2

20
C 7.4 14.7 73.6

0
C 8.0 16.0 80.0

20
C 8.6 17.3 86.4

40
C 9.3 18.6 92.8

100 80 60 40 20 0 -40

-20 1000 mb

0 500 mb

20

40

100 mb

Fig. 5.1 Baric step variation depending on air temperature and atmospheric pressure for the Black Sea coastal area

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spatial distribution of the atmospheric pressure on the open sea, and even the sea presence, together with a series of geographical factors, such as the position on the globe, in Europe, and the nature of its shores, all have a contribution. Therefore, during the wintertime, the distribution of the atmospheric pressure is as follows: two depression centers L, one in the west and the other one in the east, and one highest pressure H in the north-eastern part (this distribution is the result of the interaction between the general circulation of the atmosphere, and the thermophysical properties of the underlying surface—the first factor determines the high-pressure area and the second one the depression zone) (Fig. 5.2). During the warm season, the distribution of the atmospheric pressure is opposite from the cold season (the causes of this distribution being the same as those from the wintertime) (Fig. 5.3). This change of the pressure distribution’s direction occurs fairly late in the autumn and fairly early in the springtime [7]. Regarding the pressure distribution at a given moment, it can be shown that in the Black Sea area it differs very much from the average pressure distribution for that period. There are 14 types of baric fields more frequently acting on the Black Sea, out of which the most important for the winds’ formation over the Black Sea being as follows: the weak gradient, the weak wind (2 m/s), the cyclone in the eastern sea part, the southern edge of the cyclone, the cyclone northern edge, the eastern edge of the cyclone, the eastern edge of the anticyclone, the southern part of the anticyclone [7].

Atmospheric pressure distribution-winter

H 1022

L L 1016 1018

1016 1018

1020 1018 1016

L Fig. 5.2 Atmospheric pressure distribution in the Black Sea during the wintertime. (Processing according to [5, 6])

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1011

Atmospheric pressure distribution-summer 1012

L

H

1014 1011

H

1011

1012 1011

1012 1011

L

Fig. 5.3 Atmospheric pressure distribution in the Black Sea during the summertime. (Processing according to [2–6])

5.1.2

The Atmospheric Circulation in the Black Sea Basin

The western circulation is the one that destroys the anticyclonic centers and expands the cyclonic ones. For the European continent, the cooling sources are represented by the polar seas, especially the Baffin Sea, and as a heat source, the subtropical area situated south of the parallel of 40
N latitude. One result of the general circulation influence on the meteorological processes in the Black Sea region is the prevalence of the air masses movements from altitude, from west to east. Not only the ordinary winds have an orientation from west to east but also the high altitude winds. The Carpathian Mountains chain influences the climate of the Black Sea, too, but the influence is not very important, because it is farther from the sea compared to the Caucasus Mountains. The Carpathians Mountains act on the air masses entering the sea, whereas the Caucasus Mountains act on those that are coming out of the sea.

Main Types of Pressure Systems and Their Influence in the Black Sea Basin The main types of pressure systems that act in the Black Sea are cyclone (Low—L), anticyclone (High—H), a ridge of high pressure, a trough of low pressure, col, and others. A cyclone is an enclosed low-pressure area system where the air masses move in a spiral shape, convergent and ascending. In the northern hemisphere, the horizontal

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movement of air mass is anti-clockwise, and in the southern hemisphere, it is moving in a clockwise direction. The genesis, the development, and the end of a cyclone had an almost permanent character and expressed in time units can have a "life” from a few hours to a few days when there are developing conditions in the atmosphere that maintain or end a cyclone. An anticyclone is a high-pressure area system where the air masses move in a spiral shape in a clockwise direction in the northern hemisphere and an anti-clockwise direction in the southern hemisphere. An anticyclone occupies a large area that sometimes can be compared to a continent. The average pressure varies between 1010 and 1040 Mb but can have values up to 1080 Mb in winter, on a continental high. The frequency of formation and the intensity depending on the active surface state and the season. This means that during winter anticyclones can be found above the continents and during summer they can be found over the ocean’s surface at medium and higher latitudes. A high frequency is recorded in subtropical maritime areas, and in both hemispheres, it can be found from August to September [8]. Above the Black Sea basin, the following weather systems can be found: – Azores high, the most critical local pressure system that is located over Europe, is the anticyclone from the North Atlantic Ocean which has its center in the Azores islands’ region. It has a direct or indirect influence on how the weather in Europe will be. It is a semi-permanent high which can be found all year round without a daily permanence. The area where it extends has some characteristics: a northerly pulsation in the warmer season and a southern trajectory in the cold season; a movement toward the east in November, December, and January, when it reaches a maximum area over Occident, and the second movement towards Europe in June and July. The intensity of Azores high is given by its central value, which is around 1020 mbar during summer and also during winter. This anticyclone is more intense in the summer, and when some exceptional conditions are met, it can reach values over 1040 Mb; – Siberian high is the third most important center of atmospheric pressure for the European climate, and, it is also named Russo-Siberian High Icelandic Low is a semi-permanent character, and it appears mostly in winter, but rarely in summer, when it lasts for a short while. Siberian high has a variable intensity from 1020–1030 mbar in Europe, and in Asia, it is more active with 1040 mbar. It can be absent in some winters, or it can take less than the whole winter because of numerous cyclones that move south or south-east from the Arctic Ocean, which causes an occupation of more than half of the eastern part of the continent and also destroys the ridge of high pressure. Sometimes when it is found in the eastern part of the sea it means that the air temperature will rise; – Icelandic low is a semi-permanent low-pressure system with a variable surface from a month to another. Its pressure varies from 990 mb in January (maximum) to 1005 mb in June, when the lowest depth is recorded. Taking into consideration the value of the gradient, the Icelandic cyclone has a higher intensity in the summer and winter. A high frequency characterizes its duration during the cold period, which means more than 80% of the time, and at the beginning of spring and summer, it has a lower frequency. These low-pressure systems are well defined and have strong winds and a large quantity of precipitation.

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121

– Mediterranean cyclones have great importance for the climate in the western and southern parts of Europe. Semi-permanent cyclones are formed in the winter period and rarely in the second part of summer or at the beginning of autumn. They begin to act from October when their surface is shorter and includes Sardinia, Corsica, and the Gulf of Genoa. In November, their area is getting bigger and includes at this point all of Italy; in December, because of the southwestern trajectory of Siberian high, and the eastern trajectory of Azores high, the Mediterranean low is becoming restrained, and is now situated mostly in the south. The average intensity is 1012 Mb, but in worse cases, it can be 990 mbar. Mediterranean cyclones act in a proportion of 41% of the year, in the Mediterranean basin, they act close to half a year, and in the Black Sea basin, they are present all year round. An unusual fact worth mentioning is that especially during winter they bring a warm and humid air mass over the cold and a dry one above Romania. They generate rain and fog, and at the beginning of their westerly movement in the Black Sea, they will bring a slight increase in air temperature with moderate to strong wind, especially on the coast; these are caused by a vital pressure decrease (980 mbar). When Mediterranean cyclones evolve they will affect the wind by changing its direction, intensify it and also drop the temperature; rain becomes sleet, and then heavy snowfall (possibly blizzard). Mediterranean cyclones can move in series within a period of 3, 6, 9. . .days, or just a few hours. – Scandinavian high is not annually present or during a certain period; it has its roots in the Scandinavian Mountains and sometimes this high-pressure system unites with the high from the Ural Mountains, making a high-pressure arc over north-eastern Europe and sometimes is connected with the Azores ridge of high pressure, which results in an anticyclonic arc over the north-west of the continent. Most of the time, it has an isolated development on the Scandinavian Peninsula that extends ridges of high pressure to the south-west, south or south-east, towards the Black Sea. Speaking of frequency, it is high in warm seasons, and during winter the weather becomes very cold (frosty) all over Europe. – The baric depressions’ movements over the Black Sea (common during the wintertime and rarely during the summertime) cause climate perturbations, such as strong winds, rain or snow, and even strong variations of temperature and humidity, all of these having negative implications for the navigation and maritime transport. The anticyclonic movements (during the winter season and occasionally during the summer season) are: from NW, originated in the North Atlantic, the eastward over eastern Europe; from the Mediterranean (Adriatic Sea) to E or NE, from Aegean Sea (during the winter season and less during the summer season) [4, 5] (Fig. 5.4). The baric fields frequency in the Black Sea basin is as follows: A, with a frequency of 49.4%—baric types that cause a movement with the same direction throughout the entire sea basin (e.g., the cyclone's western edge and the eastern edge of the anticyclone; the cyclone’s eastern edge and the western edge of the anticyclone; the southern edge of the cyclone and an anticyclone in the southern part of the sea; the northern edge of the cyclone and the southern edge of the anticyclone); B, with a 17.6% frequency—baric types that determine different movements in the west and east parts of the sea (e.g., cyclone in the western, eastern, and central parts of the

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From the North Atlantic The Anticyclone conditions basin

From Adriatic Sea

From Aegean Sea

Fig. 5.4 The anticyclone conditions in the Black Sea basin. (Processing according to [2, 5, 6])

sea); C, with a frequency of 33.0%—small gradients types and with a low frequency (e.g., small gradient and anticyclone in the western and central parts of the sea) [6]. The Black Sea has a peculiarity, its presence in all seasons of the cyclone from its eastern part, with a frequency of 9–10%, which is specially formed due to the influence of the relief conditions (e.g., the Caucasian Mountains chain) [7]. According to Russian scientists Surkova et al. (2013) [9]: within the variety of the atmospheric circulation governing the climate of the Black Sea, there are two main types of sea level pressure field derived by cluster analysis and associated with SWAN (Simulating WAves Nearshore) wave model storm days. The first circulation-type CT 1 (57% of events), the trough moves to the Black Sea from the eastern Mediterranean Sea in Anatolia, Western Asia, and often forms an independent local cyclone over the Black Sea. If the center of the cyclone is located over the southern part of the Black Sea or Asia Minor, prevailing winds are NE, E, and SE. At the same time, a vast anticyclone overspreads European Russia and Western Siberia blocking the northward movement of the southern cyclone. The second type CT 2 (the other 43% of events) is characterized by a low-pressure center over the northern seas (Barentz or Norwegian) (Fig. 5.5).

5.1.3

The Winds’ Regime in the Black Sea Basin

The winds’ regime results from the general circulation of the atmosphere that is based on the planetary scale pressure differences. The wind represents a tabular structure horizontal circulation of the air masses, which is always performed from high pressure to low pressure in the baric gradient direction. The size of the baric gradient determines the intensity of the wind in the sense that, in case of a small

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123

Fig. 5.5 Source: Surkova et al., Atmospheric circulation and storm events in the Black Sea and Caspian Sea [9]. By courtesy of Prof. G. Surkova

gradient, the winds are of small intensity up to calm winds, and in case of a high gradient, the winds are strong and can reach a force of 12 Beaufort units in extratropical areas, or even above this force (13–17 Beaufort, respectively), in tropical cyclones, or some cases, of polar winds. The winds' speed is expressed in m/s, km/h, Nd, or on the Beaufort Wind Scale, and roses express the wind regime with percentage distributions of the speed on eight wind directions. In the wind's regime can be encountered areas and periods characterized by light or calm winds, zones and periods characterized by strong winds, prevalent in certain directions. Also, the winds' regime has important implications in a range of economic activities, including maritime technology and marine navigation. The wind from the Black Sea basin has the following characteristics: during the winter season, as a result of the influence of the sea’s depression and the Siberian anticyclone ridge, the winds from the northern sector (north-west, north, and northeast) are emphasized, very strong along the coast and weaker on the open sea; during the summer season, the north-west winds, west, and south-west are prevailing in the western part of the Black Sea, and from the sea towards the land in other parts of the sea, as a result of the Azores maximum predominance. For the Black Sea basin, the wind speeds distribution on speed steps is as follows: 40–50% speeds within 1 and 5 m/s, 35–40% speeds within 9 and 10 m/s, 25% speeds within 12 m/s; speeds within 11 and 15 m/s during the winter season (i.e., the frequency of winds having speeds bigger than 15 m/s does not exceed 3–5%, not more than 10% during winter [6]). This feature of the winds’ regime, with prevailing low and moderate wind speeds throughout the year favors navigation in the Black Sea. The northern sub-basin is characterized by the highest mean of seasonal values (7–8 m/s in winter), while these decrease to 3–4 m/s in the Eastern part. In particular, for the Romanian coasts, January presents the largest number of days with windy events [2, 7]. The evolution of atmospheric moisture simulated suggests a relative increase of columnar water vapor over the entire basin in the interval 2011–2040 compared with the long-term model climatology (1961–2000). This increase is more significant in

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the north-western part (up to 12%), and it is in the order of 7% in the Southern area which also shows more projected episodes of moderate and strong winds in the interval 2011–2040. Such combinations could imply changes in the statistics of severe weather events over the Black Sea in the following decades [10]. The types of wind circulation in the Black Sea area, depending on wind directions (determinations based upon the baric field’s distribution on the sea and its surroundings) are as follows: north-east, east, south-east, south-west, west, north-west, north, and weak circulation. The most likely time average for these types of circulation is 6–24 h, with a frequency of 67% of the cases (for the cyclonic circulation, the period within 6–12 h is met in 77% of all cases). It must be mentioned that the north-east circulation has the biggest average annual continuity, respectively 29 h; the monthly average of this type of circulation shows that this is more persistent during winter (i.e., 41 h), having a maximum duration of 110 h. The cyclonic circulation of 9 h has the lowest annual average duration. Taking into consideration the phenomenon of its appearance, the north, and north-east circulation is the most stable and the cyclonic circulation is the most unstable. Specific to the circulation determined by the thermophysical properties of the underlying surface of the Black Sea is the presence of the breeze acting seaward around 09:30; then it intensifies around 14:00–15:00, weakening afterward, it changes the direction from land towards the sea, around 19:00–20:00, respectively. The breeze is important in the formation and establishment of the coastal climate by direct action on the temperatures of the warm season, even in areas placed at distances of many kilometers inland. Recent research (E. Rusu et al., 2018) on spatial distributions of the wind speed, wind direction, and the mean significant wave height computed as the average of the total data for the 20 years, 1997–2016, have revealed the following main characteristics (Fig. 5.6) [11]: – For the wind speed, the maximum mean value reaches 7.14 m/s in the middle of the Azov Sea, and between 6.5 and 7 m/s in the western part of the Black Sea basin. – The highest average values for the spatial distributions of the wind speed are encountered during the winter season, with a maximum around 8.24 m/s. – The spatial distribution of the mean significant wave height shows that the mean significant wave high values reach 1 m in the center and southwest of the Black Sea basin, and the average of wave high values in the eastern part of the basin do not exceed 0.9 m in any offshore zone. – The average significant wave heights have maximum values in the winter, 1.44 m, in the middle of the western part of the basin, and also in a small area located near the east coast, there are values around 1.4 m. The average values corresponding to the central part of the basin are also high, around 1.3 m. The spatial distributions of the mean wave high have similar patterns in spring and autumn. – In the summer season, a more uniform wave field than in all the other seasons is observed, the higher values (around 0.8 m) being located in the southwest of the Black Sea.

5.1 Anemobaric Regime, Atmospheric Circulation, and Wind Regime in the Black. . .

125

Fig. 5.6 The spatial distribution of the mean wind field—left and the mean significant wave height field—right panels, for 1997–2016 period, and for winter, spring, summer, and autumn seasons, from top to bottom. (By courtesy of Prof. E. Rusu [11])

Regional Winds in the Black Sea Basin There are several types of local winds in the Black Sea basin, such as [6] (Fig. 5.7): – Bora, NE wind, violent, in the adjacent area to the port of Novorossiysk – Trampontan, on the Bulgarian coasts, and those of the Crimean Peninsula (destructive force in the Yalta area) – Levan, southerly wind, humid, frequently during the cold period of the year, offshore and can produce strong swell – Not, south wind, strong and humid, on the north coast, bringing rain and fog – Harbiy, south wind, on the Crimean coast

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Black Sea KHERSON ODESA

Local winds

CHORNOMORS’KE KERCH SULINA

Ponente

YALTA

Not

NOVOROSIYSK

Bora Foen

CONSTANŢA

TUAPSE

ADLER

Ponente Harbiy

VARNA

Trampontan

Foen

Karadzhol

BURGAS

Melteni Lodoz

Levan BATUMI

ISTANBUL AIRPORT

ZONGULDAK

Katabatic winds

SAMSUN

TRABZON

Fig. 5.7 Black Sea—local winds

– Boneti (Ponente), strong westerly wind, on the Bulgarian coasts and those of the Crimea, brings occasional rains – Karadzhol, west wind, on the Bulgarian coasts, brings rain – Lodoz, south or southwest wind, warm, on the west coasts, summer and autumn, accompanied by good weather – Katabatic winds, from the southeast, on the coasts of Turkey, in winter – Dry winds, of the foen type, on the slopes of the Caucasus and Crimea mountains

5.2

The Air Masses and the Atmospheric Fronts in the Black Sea Basin

The Black Sea can be considered a confluence zone of different air masses. The air masses having different physical properties are separated by transition zones, where the meteorological elements have significant variations. Such areas are called "frontal," and their intersection with the active surface—atmospheric fronts. The air masses play an important role in weather changes, especially in extratropical baric depression areas. The width of a frontal area is in the range of a few tens of km, but its development in a vertical direction is limited to a few kilometers, exceptionally reaching the troposphere. As the dimensions of the transition zones (i.e., frontal) can be tens or even hundreds of times smaller than the dimensions of air masses, the air zones can

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127

be considered frontal surfaces, and they are represented by lines on the meteorological maps, obtained by their projection on the earth’s surface. The frontal surfaces are always inclined towards the cold mass, because of the higher density of the cold air; the inclination is strong, and it forms small angles with an active surface, usually the angles being of 10
. The basic fronts (i.e., permanent) are separating the main air masses, which are considered at a global scale. Depending on the position, the main air masses are Arctic (Antarctic); the maritime and continental variants: mA and cA; polar with variants mP and cT; and tropical with variants mT and cT and equatorial.

5.2.1

The Air Masses and the Atmospheric Fronts in the Black Sea Basin

In the Black Sea basin, the following air masses are acting: artic, having the origin in the North Pole basin, characterized by low temperatures, low watery vapors content, and big transparency; maritime polar or continental polar, formed at middle latitudes; tropical, forming over the tropical zones; maritime (characterized by relatively high temperature and high moisture) and continental (characterized by very high temperature, low moisture) [2, 4]. The polar continental air enters the Black Sea region with the strong north-east winds, caused by the Polar meridional circulation and the Siberian anticyclone ridge, resulting in the strong cooling of the atmosphere, especially in the north-western sector. The polar maritime air (i.e., unstable) enters in the western part of the thalweg formed by the polar meridional circulation and causes an increased nebulousness and high rainfall. The continental tropical air rarely penetrates from the south of Russia, and the maritime air, respectively, of Atlantic origin, penetrates from the southwestern direction. The air of artic origin entering the Black Sea basin is uncommon [2, 6]. The frequency of different types of air masses over the Black Sea throughout the year is shown in Table 5.2 and Figs. 5.8 and 5.9; the predominance of the Arctic continental air (51%), followed by the tropical air (22%), the Arctic maritime air (15%), and finally the artic air (12%), can be observed. The winds’ regime from the Black Sea surface is influenced by the tropical continental air that rarely penetrates, coming from central Asia; the tropical maritime air has an Atlantic origin, and it penetrates the Black Sea during the prevalence of the south-west air currents. During the winter season, the penetration of this air type is accompanied by substantial heating of the Romanian seaside. The polar meridional circulation conditions the arctic air entering, but it is very rare because the arctic air may not always reach the Black Sea regions. A direct result of the general circulation influence on meteorological processes in the Black Sea zone is the predominance of the air masses’ movement from altitude, from west to east, respectively, not only the ordinary winds but also the strong ones,

I 19,8 4,6 2,7 3,9

II 14,2 5,7 3,8 4,8

III 21,9 2,1 3,1 3,9

IV 17,8 3,8 5,0 3,4

V 18,6 1,3 8,8 2,3

VI 12,0 6,0 10,3 1,7

VII 6,2 6,7 17,5 0,6

VIII 10,0 7,2 12,1 1,7

IX 14,5 3,7 4,8 7,0

X 15,0 4,1 6,5 5,4

XI 15,2 4,0 6,1 4,7

XII 19,81 4,6 0,4 4,3

Sum 185,0 53,8 82,6 43,6

% 51 15 22 12

5

Month Air mass Polar continental Polar maritime Tropical Arctic

Table 5.2 Frequency of air masses over the Black Sea

128 The Black Sea Basin’s Meteo-Climatic Characterization

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129

Fig. 5.8 Frequency of air masses over the Black Sea, % annual

Polar connental Polar marime Tropical Arcc

25 20 15 10 5 0 Polar connental Polar marime I

II

III

IV

V

VI

Tropical VII

VIII

IX

Arcc X

XI

XII

Fig. 5.9 Frequency of air masses over the Black Sea, % monthly

of high altitude, that have an orientation from west to east. The exceptions are rare and short in duration, respectively when the retrograde circulation occurs, that may be present in a depression, as well as the Siberian atmospheric maximum, too. A duration of 3–5 days characterizes the NE circulation type and a maximum speed of 23–25 m/s, in comparison with the NW type, which is characterized by a short duration, i.e., of 2–3 days, but having maximum speeds, of 28–32 m/s. For the southern circulation, where the maximum speed is 17–19 m/s, the duration is less than two days. That the southern circulation makes the evident bigger stability of the troposphere than previous circulation types was demonstrated. Slight warming may occur during the winter season when the southern circulation brings warmer air from the sea (e.g., on February 1–10, 2000, in Constanța, the temperature was above 10
C, 14
C in the country, respectively). Sometimes, during the summer season, insignificant cooling is noticed because of the southern warm air cooling, while the sea temperature is lower. The baric situation in which the NE circulation is realized is characterized by maximum Siberian lowering to smaller latitudes, and depression from southern latitudes approaching the Black Sea, thus, the baric gradient in the area is increased. The NE circulation is characterized by a very cold advection from the area located in the north-east of the Black Sea; therefore, the thermal contrast between the existing air mass and the approaching one sometimes reaches 25
C (e.g., between 10
C and +15
C). A relation is noticed between the thermal contrast and the duration of the storm, i.e., with the difference increasing, the wind becomes stronger; the

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potential energy turning into kinetic energy is in direct conjunction with the thermal contrast between the air masses that come into contact. The north-west circulation is characterized by a much lower thermic contrast between the two air masses, 10–15
C, but a large temperature gradient is typical. This happens because, simultaneously with a cold advection from the northwestern Black Sea, a warm advection occurs in the south-eastern part of the sea, a case in which the local baric gradient increases locally very much, reaching sometimes 7–8 Mb/100 km. The storms in this category are very violent, and they are in strong conjunction with the baric gradient, the wind speed reaches 30 m/s, but they have a relatively low duration, of 2–3 days. As a consequence, the thermic contrast is lower compared to the previous case, where the duration was 3–5 days. Following the same correlation between the wind intensity, the baric and thermic gradient, the same phase difference, i.e., of about 6 h, can be observed between the extremes of the baric gradient and the wind speed. The thermic gradient values are very high at the height of the storm. Referring to the wind direction, that is prevailing from NNW, the maximum of Azores is centered on Europe, extending a dorsal westward to the Black Sea. The northern area of the sea is under the influence of a depression field having multiple cores. In our area, the southern circulation is distinguished by a minimal value of the gradient and the thermic contrast. Most situations with strong winds from the southern sector are associated with a tropical circulation with jets-oriented SN in our country’s area. The storms of this type do not present special intensification of the wind, do not exceed 18 m/s and do not have a big duration, the maximum being off two days. As regards the share of the baric centers and their distribution on seasons, generally, the situation is as follows: during summer, when the Azores anticyclone dorsal covers the Eastern Mediterranean, the tropical air penetrations occur, that produce clear weather, relatively dry and warm air. In the situation of the same anticyclone, when the dorsal is withdrawn to the west, at its northern periphery the cyclonic series from the Atlantic are moving over the continent, that, initially, conduct their trajectories to the south-east, then are recurving to north-east, also passing frequently over the Black Sea basin. This leads to the appearance of relatively moist and less warm maritime air at the Romanian seaside and adjacent maritime areas. During summer, but with a lower frequency, anticyclonic ridge influences may occur from the European part of Russia, determining the southern circulation of continental air masses, characterized by dry and hot winds. In the summer season, during the warmer months, because of the Azores anticyclone’s influence, the winds from the western Black Sea are blowing from northwest, west, and south-west directions. In the rest of the year, during the summer, the main direction of the coastal winds is from the sea to the land. During the winter season, the air circulation from the Black Sea’s western basin is characterized by variability and high intensity, due to the processes occurring, especially, through the presence of the powerful Siberian anticyclone. The strongest temperatures’ dropping is caused by the penetrations of the polar air masses from the

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131

eastern edge of the Scandinavian anticyclone, but especially by the polar air overrun from the north-east and east, along with the south-west periphery of the Siberian anticyclone. The air movements are fast, causing plentiful snowfalls, temperatures dropping, and strong winds from northern or eastern sectors, when over the Mediterranean Sea and the Black Sea the cyclonic activity is intense, especially when the baric depression is centered right in the Black Sea area. The blizzards occur, the sea is extremely agitated, and sometimes, the sea waters’ freezing phenomenon occurs in the northwest parts (e.g., in February 1996), when the baric depression is moving to Anatolia. During the winter season, due to the depression center over the sea and the influence of the Siberian anticyclone ridge, the Black Sea is under the action of the northern sector’s winds. In the transition periods, especially during the spring season, the baric depressions from the Mediterranean Sea have an important influence on the Black Sea area; they generate cyclones that are moving towards the Black Sea basin and cause unfavorable weather, with drizzle, fog, wind intensifications, sea’s turbulence, etc. The number of cyclones passing annually through the Black Sea area has an average between 11 and 28. It is true that some of the cyclones’ evolution only allows them to cross the area, i.e., they do not undergo significant changes during the described trajectory. The cases of obstruction are prevalent, i.e., without strong winds, below 10 m/s, respectively. Regarding the cyclones generated on the Black Sea surface, they are more numerous than those who undergo occlusion processes, and also, they have higher wind speeds, i.e., storm winds. Also, another characteristic of the cyclonic fields is their duration; it is worth mentioning the high frequency of the cases when their duration is of several hours, up to one day; 60% of all the cyclones that cross the Black Sea area have these features. The Black Sea winds’ regime can be characterized as follows: the winds dominance depends on the region, the winds from the north-west, north and north-east are met on the north-west shores with a probability of 50% (in the Danube Delta and to the south of Bosporus the winds from the north and north-east are prevailing); during the spring time, the north-west and north-east winds are prevailing; during the winter time, on the western shore of the Crimean Peninsula the wind from the north-east is prevailing (30–40%), during the spring time, the south wind (20–25%), and during the summer time, the winds from the north-west (25–30%) and north-east (19–20%); in the Kerch Strait area, the winds from the east and north-east prevail throughout the year (30–45%), but, also, those from west and north-west are important, too; on the Caucasian coasts the winds from the south and south-west are prevailing at a rate of 40–55%; on the Anatolian coasts, during the cold season, the south and south-east winds are prevailing, as well as the north-west and north-east, as squalls, and during the summer season, the winds are weak and moderate from all directions; during the spring and autumn seasons, they have unstable directions. The annual wind speed average does not exceed 7 m/s in coastal areas, the multiannual maximum being recorded at the river mouths of the Danube Delta, at Cape Tarhankut, the Kerch Strait, nearby Novorossiysk, the Romanian and Bulgarian coast, and the minimum wind speed being recorded in the area of the

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mountainous coast. Generally, the strong winds’ direction (i.e., with speeds exceeding 15 m/s) coincides with the direction of the prevailing winds; the windy days’ average is 38 days in Odesa, 44 days in Sevastopol, 29 days in Kerch, 55 days in Novorossiysk, 20 days in Batumi, and less than 27 days in Trabzon, Samsun, and Eregli. The maximum wind speed was recorded in the Tendre’s tongue area (41 m/s, respectively), and in Sevastopol, Novorossiysk, Tuapse, Poti, Batumi, Sinope, Eregli, Constanţa, and Varna areas as well (i.e., over 40 m/s).

5.2.2

The Storms Regime in the Black Sea Basin

In her appreciated doctoral thesis, Romanian scientist Chiotoroiu (1998) studied the evolution of storms on the Black Sea’s western part, from 1974 to 1993, and concluded: storms are more frequent from October to April (185). The 3 types are identified through the location of atmospheric centers at sea level. The I type (over 52%) is the couple anticyclone/depression (with traveling disturbances from the Mediterranean Sea to the Black Sea). The II type, storms in an anticyclonic situation (over 24%), are created in a high-pressure field (with the presence of Mediterranean disturbance or with lowering pressure on the eastern part of the Black Sea). The NNE strong winds at the periphery of the continental anticyclones blow along the Romanian coast. The III type storms in the low-pressure field, 19% are the consequence of traveling low-pressure systems from the Atlantic or from the Mediterranean Sea to the Black Sea. Winds blow from various directions, but the strongest is the north ones. These storms are weaker than the I and the II type [12]. According to Bulgarian scientists Galabov and Chervenkov (2019) [13]: in the Black Sea basin, severe storms do occur when the waves may reach significant wave heights, comparable to those during the oceanic storms. These sea storms may cause huge damages to the coastal infrastructure and environment, sinking of ships, loss of human life. Some of the most notable storms are on the northern coast, e.g., the Kerch storm of 2007, and storms causing damage along the western coast, such as the storm of February 1979 and the storm of February 2012. It is generally accepted that the storminess in the Black Sea is higher in the western part of the basin. This conclusion is confirmed by many studies based on numerical wave hindcasts. By Russian scientists, Lopatoukhin et al. (2009) [14], a classification of the Black Sea storms and the average of parameters of storm classes are as follows (Table 5.3 and Fig. 5.10): I. Storms, orientated along a parallel, start in the western part of the sea and run out in the same place. II. Storms, orientated along a meridian (from Bosporus to Odesa), start in the western part of the sea and run out in the same place. III. Storms, coming into the east part but bent to the east coast. IV. Storms, coming into a northeast part.

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133

Table 5.3 Average parameters of storm classes [14] Class Height of a wave in the storm center, m Time of a life of a storm, h The equivalent radius of a storm, km The average speed of a storm, km/h

I 7.6 19 127 8

II 7.0 8 69 4

III 7.4 12 116 12

IV 7.3 11 94 10

% 36 22 16 26

Fig. 5.10 Black Sea storm classes in % I class

26

36

II class III class

16 22

IV class

Their statistical characteristics of Black sea storms, based on the SWAN simulations are [14]: – The more storm threshold (adopted wave height) the less is the total number of the storm (from 2289 up to 46). – There can be some independent storm simultaneously in different parts of the sea. – Average and maximal time of storm duration decreases with increase in a level (from 25 till 13 h), also a maximal time of life (for 9 meters—90 h). – The equivalent radius starts to increases with the growth of a level and then decreases slightly. It is connected with the limited size of the Black Sea. – The length of a trajectory of a storm decreases with an increase in a level (from 1395 up to 400 km), as well as a time of a life of a storm. – An average speed of moving of a storm is 5–9 km/h; however, the maximal speed can achieve 31 km/h, this happened in the storm of November 2007, and it is typical of oceanic areas. After Vespremeanu-Stroe et al. (2016) [15]: the Black Sea western storms are high-energy repetitive events (strong winds and high waves), which are generally the result of Mediterranean cyclones with different trans-Balkan trajectories. From the analysis of long series of wind (1962–2012) and wave (1949–2013) data, resulted that on average, there are 30 storms/year with a distinct seasonality, of which approximately 3 events/year correspond to severe storms (speed wind  20 m/s; significant waves height  4 m) that occur during the active season (October–March). The highest concentration of severe storms was recorded between 1967–1973, including two extreme events in 1969 and 1973, characterized by wind speeds of up to 28 m/s, wave heights at a sea of up to 10 m, the highest high total wave strength, and the longest wave duration with heights of more than 4 m. In terms of intensity, the period 1991–1998 is the second energy range in the major

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impact on the coast of the Danube Delta. These storms were characterized by waves of 8–10 m, lasted 4–7 days and were very strong due to winds in the NE sector (25– 30 m/s). Three periods of moderate storms were identified: 1958–1966, 1974–1981, and 1999–2005, with less frequent storms, but extreme events such as the February 1979 storm, the second strongest, also occurred. storm in the analyzed range. The storm waves lasted 8 days, reaching heights of 10 m, causing flooding in Sfântu Gheorghe village, erosion, and damage to the coastal infrastructure in Bulgaria. In his study, An Analysis of the Storm Dynamics in the Black Sea, the Romanian scientist L. Rusu (2018) [16] concluded: the extreme storm waves are higher in the recent past than there will be expected in the near future. The annual maximum series shows that in the period 1987–2016, there were four years with maximum significant wave heights greater than 12 m (1992, 1999, 2004, and 2007), while in the near future, covering the 30 years 2021–2050, no such situation is expected, the maximum value of the significant wave height predicted for the entire 30-year period being 11.45 m. An increase in terms of the maximum wind speed of about 5 m/s is expected while in three years the maximum wind speed would be even greater than 30 m/s. The extreme waves expected in the near future will be smaller in terms of significant wave heights than in the past. Another tendency that is noticed for the near future period is a migration of the location of the peak storms from the southwest and the center of the sea to the west and the north, coming closer to the coastal environment in the northern part of the Black Sea (Fig. 5.11). Also, regarding the storms in the Black Sea, Todorova et al. 2018 [17] presents conclusions similar to those of the above authors: the western and north-eastern parts of the Black Sea have the most intense storms, with waves estimated as 7.8 m in height and period of 11.0 s with a return period of 100 years, maximal possible height being over 14 m. Over 50% of storm events identified for 32 years are the consequence of "coupling" of a continental anticyclone with a Mediterranean cyclone arriving over the Black Sea. Extreme storms in the NW region have a mean recurrence rate of 7 years and are considered to be responsible for the sediment transport south from the Danube delta coast. Critical thresholds for storm impacts on Bulgarian coastal morphology showed that storms with integral wave energy varying within threshold values 0.4–0.7  106 Jm2 are regarded as capable of causing significant morphological changes. Estimations of wave height with return periods between 1 and 100 years, based on SWAN models showed that waves of over 8 m height are common during autumn storms, occurring about once in 10–20 years.

5.2.2.1

Meteosynoptic Elements in the Western Black Sea Sector, the Siberian Baric Depression Coupling with the Mediterranean Baric Depressions. Atmospherical Fronts

The climate of the Black Sea western basin coasts has a continental aspect, with a strong influence exerted by the sea, both thermal and dynamic (by changing the thermic balance and changing the underlying surface roughness), so that there is great variability in atmospheric circulation, with winds with high instability degree

5.2 The Air Masses and the Atmospheric Fronts in the Black Sea Basin

135

Fig. 5.11 Geographical location of significant wave height (Hs), annual maximums registered in the 30-year time interval 1987–2016, represented by yellow circles against the Hs annual maximums expected in the 30-year time interval 2021–2050, represented by magenta circles. (By courtesy of Prof. L. Rusu [16])

(in direction and speed), generally weak and moderate, as storms are rare (usually, the storms occur every few years). The western Black Sea Basin is under the influence of the following types of weather: anticyclonic, cyclonic, north-eastern, and southern. The anticyclonic type is created by the existence of an anticyclone in southern Europe, above the western basin of the Black Sea (indeed, almost above the entire basin) acting through its southern part in moving to the west. The frequency of this type of weather is 60% during summer when it determines a relatively stable, good weather, long period of sunny days and breezes, and less than 30% in winter (only when the center of the atmospheric maximum is above the Black Sea), where it determines a cloudless time. The cyclonic type is determined by the passage of cyclones over the Mediterranean Sea. It is accompanied by south and weak northwestern winds (force 4–7); in summer it determines cloudiness due to lower and medium clouds that produce rain and clouds with lightning, cold fronts crossing and, during winter, nebulosity, and heavy precipitation. The powerful type of cyclone has a reduced frequency and is accompanied by storm winds and heavy rainfall (during transition seasons and in early winter). The north-east weather type is conditioned by the existence of the north-eastern European anticyclone, and the cyclonic activity in the Black Sea, and is characterized by strong north-eastern winds, cold exacerbating in winter, and the phenomenon of "boiling sea"; the frequency of this type of weather is 28% in the northern part of the basin (winter) and 13% in the south. The southern type of weather is formed when there are high pressures in Asia Minor, and from the western Black Sea, deep cyclones approach and cause fog, southern winds with 4–7 force, moderate nebulosity in winter.

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The Black Sea Basin’s Meteo-Climatic Characterization

It can be shown that above the western Black Sea basin, the Siberian coupling with Mediterranean baric depressions occurs with seasonal variations, as follows: – During winter: The ridge influence of the maximum Eurasian Siberian, and Icelandic thalweg depression occur, the atmospheric fronts being under the influence of the western circulation – During summer: The Azores dorsal ensure relative stability of the weather – During the transitions' seasons: When the Atlantic and Mediterranean baric depressions’ influence is expressed

5.2.2.2

The Wind Regime in the Western Basin of the Black Sea

During winter winds, from the north-east, north-west, and north, whose strength decreases significantly offshore, prevail. With the start of the warm season, winds from the sea to land prevail, and depending on the aspect of the shore, is characterized by great diversity. The annual variation in wind speed is relatively regular with a maximum during winter (Fig. 5.12) and a minimum during summer (Fig. 5.13). Monthly wind rates average values are: 6 m/s in August, 7 m/s in September– October, 8 m/s in November, and February 7 m/s in February–April, and 6 m/s in May–July. During winter the winds from north-east (from east in the south-eastern part of this area) are predominant stronger winds of Beaufort 9–10
force (5% frequency) are from the north and west, storms are frequent in the north-west and south-east of the west basin; during summer, the winds are weaker, generally, from the west (in the south-east area prevail those of the north east), over 6
Beaufort force are rare. On the southern coast, from Trabzon to Zonguldak winds from north-west prevail by day and from the south-east by night [18].

5.2.2.3

The Wind Regime in the Eastern Basin of the Black Sea

In the Black Sea’s eastern basin, between July and April, the winds of east and southeast predominate. In May, there is no predominant wind direction, and in June the south-west wind predominates. On most of the eastern coast, the north-east wind predominates (18–56%) throughout the year, however, at some points, between April and August, the W wind predominates (22–23%). In the port of Batumi, the highest frequency has the south-west wind (18–29%), and from November to January, the south-east wind (18–21%). In the port of Novorossiysk, the wind from the north-west predominates (17–35%), and only from April to June, the wind from the south-east predominates (23–30%). In many places on this coast, you can see deviations from the wind regime, determined by local geographical features. For example, between the port of Anapa and the port of Tuapse, Bora can have gusts, that can exceed 40 m/s. On the slopes of the Caucasus and Crimean Mountains, dry winds, sometimes gusts, are formed, accompanied by

5.2 The Air Masses and the Atmospheric Fronts in the Black Sea Basin

137

4

7 6

4

6 8 7 7

8

6

5

4

7 6 5 4

Fig. 5.12 Annual variation in wind speed

4 5 5

2 10

5

15

20 25

Fig. 5.13 Annual variation in wind speed (during winter and during summer)

rising air temperatures (most often between the port of Sevastopol and Cape Kersones, in the area of the port of Batumi or others off the coast of Anatolia). Also, in the area, there are frequently strong winds in the area of Tuapse port. In this

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The Black Sea Basin’s Meteo-Climatic Characterization

Fig. 5.14 Percentage frequency of Beaufort force 7 during winte wind

5 5 10 5

15

20 25

region, the percentage frequency of winds exceeding Beaufort force 7 in winter is between 5% in the central area, and between 15% and 25% in the southeast (Fig. 5.14), and in the warm season, between 2% in the central area and 4% in its northern area (Fig. 5.15) [2, 6].

5.3

The Thermohygrometric Regime. Effects on Temperature Variation and Humidity. Weather Phenomena

Air temperature designates a status parameter, expressing by the timing and on a conventional scale the heat of a body, as a result of its internal energy, and of the exchanges of energy with a thermal effect, which that body carries out with other bodies or with the environment. The body considered is the Earth’s atmosphere, namely, the part of it called the troposphere. Air temperature is the main meteo element involved in correlation with the atmospheric pressure, and its variations in space and time analyze a large number of physical processes and meteo phenomenal space and time. Its diurnal, seasonal, and annual variations depend on the position, latitude, and the nature of the active surface (land, sea) and are extremely important to marine activities.

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

139

Fig. 5.15 Annual variation in wind speed exceeding Beaufort force 7 during summer

4

2

In space the temperature variations are pursued through isotherms, thermal is abnormalities, and horizontal and vertical thermal gradients. On the Earth’s surface thermal gradients are influenced by the thermal behavior (capacity, thermal conductivity), distinguished between land and sea; in altitude, direct thermal stratifications, thermal inversions, isothermal layers are produced, and the development of medium vertical thermal, dry adiabatic and wet adiabatic gradients is being traced.

5.3.1

The Air Temperatures in the Black Sea Basin

The climate conditions of the Black Sea basin are very different both in the coastal areas and into the open sea, due to the seas' expansion to almost 6
latitude. The north-west sector often enters deep into the Ukrainian steppes, where, in the winter season, the north-east winds strongly cool the shores and the waters in proximity; on the contrary, the mountainous southern shore defends well the land and the sea from cooling, resulting in a higher temperature in this area of the Black Sea. The temperatures recorded in different points of the Black Sea basin (and on its coasts) processing are presented for the cold season in Fig. 5.16, for the warm season in Fig. 5.17, and the annual average in Fig. 5.18 [compilation after 2, 5, 6].

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The Black Sea Basin’s Meteo-Climatic Characterization

Average air temperature – cold season

-1.0 -2.0 0.0 0.0 1.0 2.0 4.0 6.0

5.0

7.0

8.0

2.0

3.0

8.0

4.0 5.0 7.0

6.0

Fig. 5.16 The regime of the air temperature average in the Black Sea basin during the cold season

Average air temperature – warm season 23.0

24.0

23.0

Fig. 5.17 The regime of the annual temperature average in the Black Sea basin during the warm season

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

141

Air temperature - annual average

10.0

11.0

10.5 12.0 12.5

11.5 13.0

11.5

13.5

12.0

14.0 14.5 15.0

12.5

15.5

13.0

13.5

14.0 14.0

Fig. 5.18 The regime of the annual average air temperature in the Black Sea basin

During the winter season, the air temperature average increases from the north (i.e., 2
C to 1
C) to the south-west (i.e., 5–6
C), and south-east (8
C), with a maximum of 8
C in the central and south-east parts of the Black Sea basin. During the summer season, the average air temperature increases from north-west (i.e., 23
C) to a maximum in the south-west (24
C) and a value of 23
C on the south-western shores of the Black Sea basin. In the Black Sea basin, the average annual temperature ranges between the values of 10
C (in the north, north-west parts), and 15
C (in the south-east part). The temperature averages recorded in different Black Sea’s ports are presented in Fig. 5.19 [compilation after 12]. It can be observed that for the ports situated in the north and east parts, the annual variation has a similar trend. During the winter season, the temperature average drops to 2 to 3
C (the lowest one in Ochakov and the highest one in Batumi, respectively), and the high-temperature average reaches 23–24
C (i.e., the higher ones in Batumi and Ochakov, but at a difference of 30–50 days between them). On the chart from the right, similar evolutions from the southern and western ports can be observed (with lower minimum negative values for Constanța, comparing to 5–7
C in other analyzed ports). The annual variation of air temperature is characterized by diversity in different areas of the sea basin. The increase is significant at the seashore, where, very often, the annual air temperature variation presents special particularities even on small portions. The lowest average annual temperatures were recorded at Odesa (+10
C), and Constanţa (+11
C), and the highest ones were recorded on the coast of Turkey (+15
C). In conclusion, it can be stated that the average temperature increases from

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The Black Sea Basin’s Meteo-Climatic Characterization

240

240

200

200

100

100

Batumi

Giresun

Novorosiysk Istanbul

Sarici Cape

Constanta

00

00

I

II

III

IV

V

VI

VII VIII IX

X

XI XII

I

II

III

IV

V

VI

VII VIII IX

X

XI XII

Oceakov

Fig. 5.19 The average annual temperature on the Black Sea coast (Legend: Left (Oceakov; Sarîch Cape; Novorosiysk; Batumi); Right (Giresun; Istanbul; Constanţa))

north-west to south-east, the annual minimum of 9.9
C was recorded in Ochakov (the Dnieper mouth), and along the north-west coast, the annual maximum of 14.7
C was recorded in Giresun, Sukhumi, Rize, 14.5
C was recorded in Samsun; the absolute temperature recorded in the north of the Black Sea was +36
C (representing the maximum) and 28
C (representing the minimum) was recorded in the Danube Delta, and in the east part the temperature was +40
C (representing the maximum) and 8
C (representing the minimum) was recorded at Batumi. In different months the intensity of the air temperature variation is uneven and generally depends on the type of synoptic processes that are taking place above the sea. After the maximum value from July, even in September, the temperature continues to fall extremely slowly when the sea continues to be under the influence of the Azores anticyclone. The increasing influence of the Siberian anticyclone has, as a result, the decrease in air temperature, especially in the north-western sea part, where the air temperature drops in September-October from 17–18
C to 0–1
C in December [2, 5, 6]. In February, in the central parts of the western basin of the Black Sea, the air temperature is of around 8
C, respectively; 2–7
C on the western coast; 1–2
C on the north-west coast; in the eastern part, about 8
C (Fig. 5.20); and in the southeastern part, over 9
C (Fig. 5.21) [compilation after 2, 5, 6]. During spring, in the transitional season, the air temperature over the sea is mainly constant, in the southern part of around 15
C, in the western and northwestern parts of around 14
C (Fig. 5.22), and in the eastern part of around 16–17
C (Fig. 5.23) [compilation after 2, 5, 6]. During the summer season, the temperatures have a small variation from one area to another, respectively in the western basin is 24
C, in the central area of the sea being 22.5
C and in the southeastern zone being up to 24
C (Fig. 5.24).

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

143

Fig. 5.20 Air temperature – cold season

1 2 3 4 5 6 7

8

In the western basin of the Black Sea, the warmest month of the year is July, and the coldest one is January. Beginning with the second half of July till the half of September, the air temperature is almost the same over the whole western basin of the Black Sea (i.e., in the coastal area it is 24–26
C, while in the central area around 22
C). By comparing the annual variation of minimum and maximum temperatures in different points of the Western Black Sea basin, it can be observed that the air temperatures are different especially in the “cold half” of the year and they almost have insignificant variations during the summer season. In the north-west part, the absolute minimum is 30
C, and the frosts of 20
C last for a few days (on the Romanian coast, the absolute minimum of 25.6
C was recorded in Sulina, and in Constanța it was 28
C). The numbers of days with the air temperature lower than or equal to 0
C is 21.8
C in Constanța; in the north-western part, it reaches 6
; and they do not exist on the southern coast. During summer, the absolute temperatures with the highest values were recorded in the north-western part (Kherson, 39.5
C), and the lowest ones were recorded in the south part (Sinop, 32
C). In conclusion, in the western part of the Black Sea’s basin, during the summer season, the air temperature is relatively stable (in July and August, the air

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The Black Sea Basin’s Meteo-Climatic Characterization

Fig. 5.21 Air temperature – cold season

6 7

8 9

8

10 7

11

temperature is always between 20 and 25
C) and in the winter season, the air temperature is less stable and often it deviates by more than 5
C from its average values. The diurnal temperature amplitude reaches values of 6–7
C during the summer season and 1.5–2.5
C during the winter season. It is also worth mentioning that autumns are warmer than springs. In the eastern part of the Black Sea’s basin, the air temperature is between 24 and 26
C), and in the winter season, the air temperature is also less stable and often it deviates by 5–6
C to 10–11
C. On the Black Sea coast, the average annual temperature is 10.0–13.9
C (Table 5.4, Figs. 5.25, 5.26, and 5.27), and it corresponds to a Mediterranean climate type (characterized by very hot and poor summers, from the point of view of precipitation, and warm and wet winters), except for the south-eastern part, which has a climate similar to the tropical one [compilation after 2, 5, 6]. In the open sea, the lowest air temperatures are recorded during January and February, and the highest ones during July and August. The increase of the average annual temperature has the orientation north-west and south-east, having a higher thermic gradient during the winter season and a relatively low one during the summer season. This characteristic regime (positive) of the air temperature in the Black Sea basin (i.e., on the coast, in ports, and offshore) has throughout the year a favorable influence on navigation and shipping, the periods of extremely negative and negative temperatures that restrain such activities, making them short.

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

145

Fig. 5.22 Air temperature – spring season

15

15

15

16

5.3.2

The Atmospheric Humidity Regime in the Black Sea Basin

The atmospheric humidity is given by the quantity of water vapors from the atmosphere. The atmosphere can be in a state of saturation (100%) or unsaturated (in this case, humidity is reduced). This follows the variation of air temperature (the water vapors tension varies from 16 Mb in the south-east to 14 Mb in north-west). The thermohygrometric regime causes atmospheric instability and convectiveturbulent variations (thus affecting the clouds and muddy systems’ formation), as well as the diminishing of visibility and a wide range of weather phenomena. The Black Sea hygrometric regime is determined by the proper sea evaporation and the Mediterranean and oceanic air advection; over the sea basin, the annual atmospheric circulation is estimated at 3600 km3 of water. For the Black Sea basin, the relative humidity average has an inverse variation to the temperature variation (Table 5.5 and Fig. 5.28). The spatial distribution of the water vapors’ tension has the gradient always oriented towards the sea; the relative humidity isolines are approximately parallel to the shore, having higher values towards the sea center [compilatior after 2–6].

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The Black Sea Basin’s Meteo-Climatic Characterization

Fig. 5.23 Air temperature – spring season

15 15

15

16

17

23

25 23 24

24

24 23

Fig. 5.24 Air temperature – summer season

25

26

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

147

Table 5.4 The temperature average in various ports of the Black Sea,
C

Port Sulina Constanţa Mangalia Varna Burgas Istanbul Airport Zonguldak Samsun Trabzon Sinop Batumi Adler Tuapse Kerch Yalta Soch Chornomorsk Kherson Odesa Average

50 45 40 35 30 25 20 15 10 5 0

Annual mean maximum temperature 30 33

Annual mean minimum temperature 12 12

Period maximum temperature 34 38

Period minimum temperature 20 18

34 35 35

11 10 4

40 43 40

18 15 9

33 32 32

4 4 2

40 39 40

7 8 6

33 33 34 34 32

2 6 9 14 5

38 39 38 46 39

8 11 17 21 13

35 36 34 33.4

14 19 15 8.9

42 41 43

23 26 24

Annual temperature average 11.1 11.2 11.2

13.9

13 13.6

10

46 43 42 41 43 40 40 39 40 38 39 38 39 38 40 34 33 34 35 35 33 32 32 33 33 34 34 32 35 36 34 30

Annual mean maximum temperature

Fig. 5.25 Annual mean maximum temperature

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The Black Sea Basin’s Meteo-Climatic Characterization

0 -20 -12 -12 -11 -10 -15 -20 -18 -18 -40

-4 -4-7 -4 -2-6 -2 -6 -5 -8 -8 -11 -9 -9 -13 -14 -14 -15 -17 -19 -21 -23 -26 -24

Annual mean minimum temperature

Fig. 5.26 Annual mean minimum temperature

15 12 9 6 3 0

11,1

11,2

11,2

13,9

13

13,6 10

Annual temperature average

Fig. 5.27 Annual temperature average

5.3.3

The Nebulosity Regime in the Black Sea Basin

The annual average nebulosity in the Black Sea basin is off about 5.6 tenths (Table 5.6). During the winter season, the nebulosity has a more homogeneous distribution than in the warm and in the transition seasons. The average nebulosity variation throughout the Black Sea is similar to the coastal nebulosity variation (Fig. 5.29). The nebulosity average variation has a co-sinusoidal variation shape with maximum values in the cold season (6–8/8), and with minimum values during the summer season (i.e., 2–4/8) (compilation after [2–6]). The nebulosity regime in the Black Sea basin is favorable for navigation and seaborne trade throughout the year, except for some periods (not too long), during the winter season.

5.3.4

The Precipitation Regime in the Black Sea Basin

The precipitation regime in the Black Sea basin can be characterized as follows: 42% of the annual rainfall is distributed during the summer season and 58% the rest of the year (Table 5.7 and Figs. 5.30 and 5.31); the multiannual precipitation average on the coast is superior to the value of the entire sea basin (compilation after [2, 6]).

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

149

Table 5.5 Annual relative humidity (%) Port Sulina

Annual relative humidity 08.00 local means (%) 86

Annual relative humidity 14.00 local mean (%) 76

Constanţa

64

70

Varna

78

66

Burgas

81

66

Istanbul Airport Zonguldak

76

60

71

68

Samsun

74

70

Trabzon

71

72

Batumi

72

69

Adler

75

68

Tuapse

71

65

Kerch

76

64

Yalta

68

66

Chornomorsk

77

69

Kherson

78

57

Odesa

77

66

Average

74.7

67

Period years 1984– 2006 1984– 2013 1974– 2013 1974– 2013 1974– 2013 1984– 2013 1984– 2001 1984– 2013 1984– 2001 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013

In the Black Sea basin, precipitation has an uneven distribution, reaching a maximum value of 2044 mm/year in SE (Batumi), 1436 mm/year in Adler, and 1367 mm/year in Tuapse; they decrease from west to east (1244 mm/year in Zonguldak, 614 mm/year in Istanbul, 535 mm/year in Varna, 219 mm/year in Sulina) (compilation after [2, 6]). In Table 5.8 and Figs. 5.32 and 5.33 are presented the annual mean precipitation and the annual mean precipitation days. Also, Figs. 5.34 and 5.35 present the multiannual average values of the precipitation, processed for the months April and November, and Fig. 5.36 the annual averages values (compilation after [2, 6]).

150

5

The Black Sea Basin’s Meteo-Climatic Characterization

90 80 70 60 50 40 30 20 10 0

Annual relave humidity 08.00 local mean (%) Annual relave humidity 14.00 local mean (%)

Fig. 5.28 Black Sea’s ports—annual relative humidity (%)

Although it has a patchy and uneven character, the precipitation regime does not have an unfavorable effect on navigation and transport in the Black Sea basin. The strong precipitation that affects especially the port loading and unloading operations are short, particularly in the western basin of the Black Sea. Good visibility is characteristic to the Black Sea area in a proportion of 63%; thus, navigation is favored throughout the year, except for some unfavorable periods (hours and, rarely, days), especially during the weather transition seasons. The fog factor, a phenomenon of special importance in navigation and maritime transport (similarly to visibility), is formed on the sea during the transition from winter to summer (e.g., the advection fog), and during the reverse passing, it is formed at the seashore; the evaporation fog is formed over the Black Sea during the transitional and the cold seasons; the advection fog is formed at the seashore (in the conditions of a weak air movement and an evident nighttime cooling). The maximum number of days with fog at the seashore and offshore, respectively (during winter or summer) is small. Therefore, it does not have a strong influence on navigation, as well as on maritime transport in the Black Sea. Due to the weak convective air movement above the Black Sea basin, the appearance of electrical phenomena is low, too. The thunderstorms occur between May and September (1–7 days/month, respectively). The waterspouts occur above the sea (i.e., at the appearance of the Cumulus clouds) during the summer and early autumn. Thus, the number of days with hail is 1–2 per year, particularly in April and May.

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

151

Table 5.6 Annual cloud cover (oktas) Port Sulina

Annual cloud cover 08.00 local mean (oktas) 4

Annual cloud cover 14.00 local mean (oktas) 5

Constanţa

4

5

Varna

4

5

Burgas

5

5

Istanbul Airport Zonguldak

4

4

4

4

Samsun

4

5

Trabzon

5

5

Batumi

5

5

Adler

5

5

Tuapse

5

5

Kerch

5

5

Yalta

5

5

Chornomorsk

5

5

Kherson

5

5

Odesa

5

6

5.3.5

Period years 1984– 2006 1984– 2013 1974– 2013 1974– 2013 1974– 2013 1984– 2013 1984– 2001 1984– 2013 1984– 2001 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013

Specific Meteoclimatic Elements Along the Romanian Black Sea Coast

The western circulation is the main element in the atmospheric transformations that occur over the European continent, in particular over Romania, of Dobrogea, as well. The Dobrogean climate and also the seaside climate are affected by the sea, as well as by a series of atmospheric action centers. From a climatic point of view, the Romanian Black Sea coast is distinguished primarily by the influence of the marine water body on the atmospheric circulation regime. Due to the absence of some natural barriers, the movement of the air masses

152

5

The Black Sea Basin’s Meteo-Climatic Characterization

On the sea/07.00

8 7 6

On the sea/13.00

5 4

On the seashore

3 2 1

I

II

III

IV

V

VI

VII

VIII

IX

X

XI

XII

0

Fig. 5.29 The annual nebulosity variation in the Black Sea basin Table 5.7 The precipitation regime in different regions of the Black Sea basin (mm), 1984–2013 Area Nord-west Nord-east West-central East central South-west South-east Average

Quantity (mm) October–March 100 116 103 98 218 293 163

April–September 93 79 59 54 138 293 117

Annual total value 193 195 162 152 356 532 280

in the atmospheric boundary layer benefits from superior kinetic energy and a relatively low dissipation of it. It is under the influence of the Danube river, the north-west winds, and the dominant currents from north and south, as well. The Black Sea seashore climate is similar to that from the vicinity of the Mediterranean Sea, characterized by warm winters and summers sufficiently scanty in precipitation, but it presents differences from the climatic conditions of the other coastal areas from the same parallel. The north-western seashore, where the Romanian seaside is situated, is also characterized by cold winters and hot and scanty–inprecipitation summers; the south-eastern part, being much closer to the mountains, has a subtropical climate, characterized by heavy rainfalls, warm winters, and hot summers, respectively. This fact is the result of the interference between the sea and

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

153

500 400 300 200 100 0 Nord-west

Nord-east

West central

October-March

East central

April-September

South-west

South-east

Annual total value

Fig. 5.30 Multiannual precipitation average

The precipitation regime (mm)

Nord-west October-March 100 April-September 93 Annual 193

W est-central October-March 103 April-September 59 Annual 163

South-west October-March 218 April-September 138 Annual 356

Nord-east October-March 116 April-September 79 Annual 195 East-central October-March 98 April-September 54 Annual 152 South-east October-March 293 April-September 293 Annual 532

Fig. 5.31 Black Sea – precipitation regime

steppe climates. The closeness of the steppe determines major air heating, low humidity, and very rare rainfalls. The average annual temperatures of July and August do not decrease below 25
C, which demonstrates that the Romanian seashore has a warmer climate than the Baltic Sea, the North Sea, and the English Channel seashores. It is notable the small temperatures’ variation from day to night, especially in the transitional seasons, because most resorts are located between two large water surfaces, the sea and the lakes. During the day, these are storing a large quantity of solar heat that is slowly relieved during the night.

154

5

The Black Sea Basin’s Meteo-Climatic Characterization

Table 5.8 Black Sea coast—annual mean precipitation, (1984–2013) Port Sulina Constanţa Varna Burgas Istanbul Airport Zonguldak Samsun Trabzon Batumi Adler Tuapse Kerch Yalta Chornomorsk Kherson Odesa Average

Annual mean precipitation (mm) 219 453 535 529 614

Annual mean precipitation days 65 87 92 90 112

Period years 1984–2006 1984–2013 1974–2013 1974–2013 1974–2013

1244 802 821 2044 1436 1367 497 616 367 443 449 777

144 147 148 137 134 128 94 108 81 94 88 109

1984–2013 1984–2001 1984–2013 1984–2001 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013

2400 2000 1600 1200 800 400 0

annual mean precipitaon (mm)

Fig. 5.32 Black Sea coast—annual mean precipitation

The analysis of the winds’ regime between 1961 and 2018 in Constanța shows the following (Table 5.9, 5.10, 5.11, and 5.12): the prevalence of the western winds (16.7%) during six months (November to January and July to September), the lowest frequency of the winds from the east (6%); the north winds are prevailing in February and October, the prevalence of the winds from the north-east in March; the winds from the northern (north-west, north, north-east) sector have a frequency of 40%, and those from the southern sector of 34%; the average annual speeds are 7.4 m/s for the north winds, 6.7 m/s for the north-eastern winds, and 4.7 m/s for the

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

155

150 100 50 0

annual mean precipitaon days

Fig. 5.33 Black Sea coast—annual mean precipitation days

The precipitation regime in the Black Sea – April (mm)

10 30

40

10 20 40 50

60

70

80

90

100

Fig. 5.34 Precipitation regime in the Black Sea basin, April

north-western winds; the winds’ frequency is of 22% in February, the winds from the north, 19.5% in May, the winds from the south and south-east, 15.9% in August and 22.6% in November, the winds from the west; the average annual speed is 5 m/s with a maximum of 5.7 m/s in February, and a minimum of 4.1 m/s in June, the highest recorded speed is 40 m/s, having a calm character (15.7%) in August, compared to 8.4% in February and December [7, 19, 20]. The breakout of the strong winds in the western Black Sea is determined by the general circulation features of the atmosphere, materialized in the barometric centers position and trajectory; the duration and the intensity of the storm depend on the

156

5

The Black Sea Basin’s Meteo-Climatic Characterization

The precipitation regime in the Black Sea – November (mm)

40 50 20 30

30 40 50

60

70

80 90 100

150

200

250

Fig. 5.35 Precipitation regime in the Black Sea basin, November

The precipitation regime in the Black Sea – Annual average (mm)

200

300 400

500 600

700 800

Fig. 5.36 Precipitation regime in the Black Sea basin—annual average

900

1000 1500

2500

N % 13.3

m/s 6.5

NE % 11.5

m/s 6.3

E % 6.0 m/s 4.3

SE % 9.8 m/s 4.1

S % 12.3 m/s 3.9

Table 5.9 Annual frequency of wind direction (%) and speed (m/s), Constanţa, 1965–2018 SW % 7.0 m/s 3.4

W % 16.7

m/s 4.3

NW % 10.4

m/s 4.6

11.9

Calm

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . . 157

N n 19.1 11.4 9.8 15.6 14.0 N n 19.1 11.4 9.8 15.6 14.0

s 30.1 17.2 .5.3 25.1 24.1

NE s 30.1 17.2 .5.3 25.1 24.1

9.8 13.6 10.6 11.3 11.0 NE n 9.8 13.6 10.6 11.3 11.0

n

s 15.6 20.5 15.4 17.6 17.3

E s 15.6 20.5 15.4 17.6 17.3 n 2.6 7.2 7.9 6.3 6.0 E n 2.6 7.2 7.9 6.3 6.0 s 2.9 6.8 8.7 7.2. 6.4

SE s 2.9 6.8 8.7 7.2. 6.4 4.2 14.0 12.7 9.2 11.0 SE n 4.2 14.0 12.7 9.2 11.0

n

s 3.4 13.7 14.7 9.3 10.3

3.4 13.7 14.7 9.3 10.3

s

S n 9.2 15.9 12.8 11.0 12.0 S n 9.2 15.9 12.8 11.0 12.0 s 8.0 15,4 10.7 10.1 11.1

8.0 15,4 10.7 10.1 11.1

s

SW n 8.6 6.3 5.8 7.5 7.1 SW n 8.6 6.3 5.8 7.5 7.1 s 6.7 5,9 5.8 5.8 6.1

s 6.7 5,9 5.8 5.8 6.1

W n 23.4 11.9 14.6 16.7 16.4 W n 23.4 11.9 14.6 16.7 16.4 s 20.5 12.4 15.4 14.8 15.8

s 20.5 12.4 15.4 14.8 15.8

NW n 13.9 7.6 11.4 9.7 10.4 NW n 13.9 7.6 11.4 9.7 10.4

s 12.8 8.1 14.0 10.1 11.3

s 12.8 8.1 14.0 10.1 11.3

9.2 12.1 14.4 12.7 12.1

9.2 12.1 14.4 12.7 12.1 Calm

Calm

5

Winter Spring Summer Autumn Average

Direction Season Winter Spring Summer Autumn Average Direction season

Table 5.10 Seasonal average values of wind frequency and direction (%), Constanţa, 1965–2018

158 The Black Sea Basin’s Meteo-Climatic Characterization

Month Speed (m/s) 0–1 2–5 6–10 11–15 16–20 21–24

I 12.9 45.1 34.6 5.9 1.3 0.2

II 14.1 45.2 31.8 7.1 1.6 0.0

III 15.6 48.3 31.9 4.4 1.1 0.0

IV 14.7 55.8 27.1 2.2 0.2 0.0

V 19.2 55.3 23.8 1.5 0.2 0.0

VI 18.9 58.6 21.6 0.8 0.1 0.0

Table 5.11 Monthly frequency of wind speed average, Constanţa, 1961–2018 VII 20.5 58.0 20.6 0.8 0.1 0.0

VIII 22.4 55.4 21.8 0.4 0.0 0.0

IX 20.1 51.6 26.3 1.8 0.2 0.0

X 16.9 48.0 30.2 4.7 0.7 0.0

XI 16.3 48.0 30.2 4.7 0.7 0.0

XII 12.3 48.4 32.7 4.8 1.5 0.1

Average 17.0 51.5 27.6 3.25 0.63 0.02

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . . 159

160

5

The Black Sea Basin’s Meteo-Climatic Characterization

Table 5.12 Seasonal frequency of wind speed average, Constanţa, 1961–2018 Speed (m/s) Season Winter Spring Summer autumn Average %

0–1 13.6 16.5 20.6 17.8 17.1

2–5 46.7 52.7 57.3 48.9 51.5

6–10 33.6 27.6 21.3 29.6 28.0

11–15 5.9 2.7 0.7 3.2 3.1

16–20 0.1 0.5 0.1 0.5 0.3

21–24 0.1 0.0 0.0 0.0 0.0

potential energy reserve, materialized in the thermic contrast of the air masses that are coming into contact with the sea surface. The average number of intense storms (i.e., lasting more than 72 h) is about 24. These values were recorded per year, for about 20 years, and the measurements were made offshore, at the station named “Gloria,” placed on the platform of the drilling installation. Also, they could be included into three types, for each type ascertaining a prevailing wind direction, north, and north-east (75.1%), north-north-west, and south, respectively, compared to those from the east and south-east (5%); on these directions, the highest average duration is recorded (i.e., 33 h for the storms from north-east and 31 h for those from the north), as well as the maximum duration (138 h having a higher speed than 10 m/s, during the storm from February 16–22, 1979, when considerable damage was inflicted in some areas of the Romanian Black Sea coast). The most intense storm was in 1981 (the maximum speed reached 24 m/s, the speed average was 17.5 m/s for 84 hours on January 8–11); the longest storm was recorded in 1991, on December 6–10, having a wind speed average of 16.9 m/s and a total duration of 102 h. For smaller periods, the wind intensity values are higher (the maximum speed of 28 m/s, the speed average of 19.8 m/s, and the duration of 36 h). The Romanian coast is characterized by pressure inhomogeneity, determined by the different thermo-physical properties of the land and the water. The inhomogeneity is expressed by the barometric gradients that are oriented from the shore to the sea during the summer season and vice versa during the winter season. Also, there are circulatory disturbances whose character is completely local and that are adding to the general circulation, the western one, but, usually, they do not produce strong and long-lasting storms. Considering the frequency and the multiannual average distribution of the air pressure, four centers of atmospheric action are distinguished, namely: the Azores anticyclone, the Icelandic cyclone, the Russian-Siberian anticyclone, and the Mediterranean cyclones. Besides these, some are less frequent, but they are important due to the weather changes they produce in Europe, the Black Sea, and the Romanian coast, as well. The Greenland anticyclone, the Scandinavian anticyclone, the North African anticyclone, and the Arabian cyclone. Taking into consideration its water volume, the Black Sea exercises an action of attenuation of the thermic amplitudes, felt both in summer, in the tropical days, and during the winter season in the coldest days, when the temperatures on the coast are the highest in Romania, often remaining positive when everywhere else they have negative values. Hard damping of the air is noticed, especially during the transition

14,5 14 13,5 13 12,5 12 11,5 11 10,5 10 9,5

161

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

5.3 The Thermohygrometric Regime. Effects on Temperature Variation and. . .

mulannual average temperatures

Linear (mulannual average temperatures)

Fig. 5.37 Sulina—multiannual average temperatures 1986–2019

seasons, as well as a developing process of the air local circulation, i.e., the breeze winds. Because of the western and northern prevailing general circulation, the sea influence is felt only on a narrow strip along the coast. In this area of Romania, some features can, therefore, be noticed that make this territory different from other climate zones, primarily due to the influence of the Black Sea, and secondly due to the particular aspects of the landscape. In other words, the coastal climate is the warmest, but also the driest in Romania. The entire eastern area is a transition zone between the two typical largest areas: the continental Dobrogea and the Black Sea waters. In the perimeter of this coastal strip occur alternations in every sense, deployments of the continental and maritime, polar and tropical air, generating changes in the autochthonous processes of interaction. Generally, the maritime climate is characterized by summers whose heat is diminished by the sea breeze, as well as gentle winters, marked by strong and west winds from the sea. Here, the highest quantity of radiations in Romania is recorded: i.e., on average, only 62 days/year are deprived of sunlight. The multiannual average temperatures measured at three meteo stations, Constanța (1886–2019), Mangalia (1965–2019), Sulina (1986–2016) are: – In Sulina 12.05
C, minimum 10.13
C (in 1987) and maximum 13.73
C (in 2019) (Fig. 5.37) – In Constanţa 11.59
C, minimum 10.3
C (in 1891, 1912, and 1987), and maximum 14.3
C (in 2019) (Fig. 5.38) – In Mangalia 11.89
C, minimum 10.0
C (in 1987) and maximum 13.9
C (in 2019), the only meteorological station in Romania where the average monthly air temperature remains positive throughout the year (Fig. 5.39). The relative air humidity on the Romanian coast has a minimum value during the warm season and a maximum during the cold season, the annual average ranging between 72% and 80%; the multiannual average is 80.6% in Constanța, 82.3% in Mangalia, 83.8% in Sulina and 82.2% on the entire Romanian coast. On the Romanian coasts, the average annual of nebulosity shows a bigger amplitude in Constanța and Sulina than in Mangalia, from the maximum of 5.8 in Constanța (in 1968, 1970, and 1974) and 4.1 in Mangalia (1990); the multiannual average of the nebulosity on the Romanian coast is 5.3 in Constanța, 5.0 in Mangalia, 5.3 in Sulina, and 5.2 on the entire Romanian coast.

mulannual average temperatures

2016

2011

2006

2001

1996

1991

1986

1981

1971

1976

1966

1961

1956

1951

1946

1941

The Black Sea Basin’s Meteo-Climatic Characterization

1936

1931

1926

1921

1911

1916

1906

1901

1896

14,5 14 13,5 13 12,5 12 11,5 11 10,5 10 9,5

1891

5

1886

162

Linear (mulannual average temperatures)

14,5 14 13,5 13 12,5 12 11,5 11 10,5 10 9,5

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

Fig. 5.38 Constanţa—multiannual average temperatures 1886–2019

mulannual average temperatures

Linear (mulannual average temperatures)

Fig. 5.39 Mangalia—multiannual average temperatures 1965–2019

The analysis of the precipitation regime of the Romanian coast of the Black Sea, for Constanța, Mangalia, Sulina, shows a distribution of the average annual values with a minimum of 137.8 mm/year (e.g. Sulina, 2000) and a maximum of 640.9 mm/year (2006), values comparable with the average annual values for the northwest part of the Black Sea. The multiannual precipitation average on the Romanian coasts is as follows: 396.7 mm/year in Constanța (Fig. 5.40), 459.6 mm/year in Mangalia (Fig. 5.41), 345.9 mm/year in Gura Portiței, 333.4 mm/year in Sfântu Gheorghe, and 361.17 mm/year on the entire Romanian coast (Table 5.13 and Fig. 5.42). This is due to barric formations that make wet masses of Mediterranean origin rich in precipitation. Constanța, rich years of precipitation: 1970, 1971, 1991, and 1997 (May), recorded monthly quantities that exceeded 100 mm. In 1970, in May, 115.4 mm were recorded in Constanța; Mangalia 105.9 mm; and in June: 1972, 1978, 1983, 1992, 1997, monthly precipitations of up to 140.3 mm were recorded at Mangalia [14]. The annual average of the number of days with snowfall on the Romanian coast is as follows: 33.1 days in Constanța, 21.6 days in Mangalia, 21.8 days in Sulina, and 25.5 days on the entire Romanian coasts. The average annual number of days with snow is as follows: Constanța 15.1 days, Mangalia 12.7 days, Sulina 0.0 days, and 9.2 days on the entire Romanian coast [14]. The average annual number of days with glaze on the Romanian coast is 2.1 days in Constanța, 1.3 days in Mangalia, 0.9 days in Sulina, and 1.4 days on the entire Romanian coast (see Fig. 5.38), having a minimum of 0 days and a maximum of 20 days (e.g., in Tulcea 1996) [14]. The average annual number of days with fog on the Romanian coast is as follows: 51.9 days in Constanța, 26.5 days in Mangalia, 33.6 days in Sulina, and 37.3 days on the entire Romanian coasts, having variations between 8 in Mangalia (1999), and 84 in Constanța (1978 and 1980); the highest number of days with fog being recorded in Mangalia and Constanța [14].

5.4 Black Sea’s Main Ports Meteorological Data Analysis

163

60,00 50,00 40,00 30,00 20,00 10,00 1886 1890 1896 1900 1904 1908 1912 1920 1924 1928 1932 1936 1940 1944 1948 1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016

0,00

Fig. 5.40 Constanța—multiannual average precipitation, 1986–2016 70,00 60,00 50,00 40,00 30,00 20,00 10,00 2015

2011

2013

2009

2005

2007

2003

2001

1997

1999

1993

1995

1991

1987

1989

1985

1983

1979

1981

1975

1977

1971

1973

1969

1967

1965

0,00

Fig. 5.41 Mangalia—multiannual average precipitation, 1986–2016

5.4

Black Sea’s Main Ports Meteorological Data Analysis

By statistical processing of these meteorological data (temperature, humidity, nebulosity, precipitation levels, distribution of winds, fog, thunderstorms) for the major Black Sea basin’s ports Sulina, Constanţa, Burgas, Zonguldak, Samsun, Batumi, Novorossiysk, Kerch, Odesa (monthly average, multiannual 1960–2018 period), the following conclusions have been drawn: – The atmospheric pressure regime: a co-sinusoidal development for the entire coast, with a maximum in winter (1019–1022 mb) and a minimum in summer (1010–1015 mb) (Fig. 5.43). – The annual mean sea level pressure on the Black Sea coast is 1016–1017 (Table 5.14 and Fig. 5.44). – The temperature regime is shown by: – The maximum monthly average (Fig. 5.45): summer, monthly highs record in July and August (30–34
C), higher in the northern and western parts, 320–340
C (Novorossiysk, Odesa, Kerch, Burgas, Constanța) than in the south, 290–300
C (Samsun, Zonguldak, and Batumi); winter, 90–140
C values in January and February in the north and west (Odesa, Sulina, Kerch, Constanța),

I 43,6 31,0 21,0 25,8

II 23,6 26,0 17,5 21,5

III 43,5 28,7 24,1 24,4

IV 29,0 39,5 25,0 21,4

V 41,9 36,1 42,0 26,5

VI 40,7 41,9 35,4 18,7

VII 63,8 35,7 23,1 32,3

VIII 25,6 31,2 27,2 35,0

IX 39,3 31,8 23,5 38,3

X 65,5 35,9 34,8 28,2

XI 28,7 37,9 32,5 29,3

XII 43,4 35,3 33,8 32,0

Annual 459,6 396,7 345,9 333,4

5

Month Meteo station Mangalia Constanţa Gura Portiţei Sf.Gheorghe

Table 5.13 Romanian Black Sea coast—multiannual average precipitation, 1986–2015

164 The Black Sea Basin’s Meteo-Climatic Characterization

5.4 Black Sea’s Main Ports Meteorological Data Analysis

165

70 60 50 40 30 20 10 0

Mangalia Jan

Feb

Constanţa

Mar

Apr

May

Jun

Gura Porţei Jul

Aug

Sep

Sfântu Gheorghe Oct

Nov

Dec

Fig. 5.42 Romanian Black Sea coast—multiannual average precipitation, 1986–2016 1025

1022

1019

1016

1013

1010 Ianuarie I

Batum i

Februarie II

Burgas

Martie III

IV A prilie V

C ons tanta

MaiVI

Kerch

Iunie V

VI Iulie

N ovoros s iys k

t Septembrie OcIX tombrie XNoiembrie VI A ugusVII VIII XI Dec embrie XII

Odes a

Sam s un

Sulina

Zonguldak

Fig. 5.43 The Black Sea ports–atmospheric pressure regime

to the lowest monthly average of 15–18
C at Samsun, Zonguldak, Batumi, Burgas; the higher amplitude of maximum average temperatures for the ports situated in the north-western sector of the Black Sea. – The minimum monthly average (Fig. 5.46): in the summer, monthly lows record is around 13–17
C values in July, August, and September, the highest in Batumi and Samsun (16–17
C), and the lowest (13–14
C) in Kerch and Sulina. – The mean annual maximum average (Table 5.15 and Fig. 5.47): from 30
C in the northwestern part (Sulina) to 35
C on the Bulgarian coast and Instanbul and 36
C in the north (Kherson). – The mean annual minimum temperature (Table 5.16 and Fig. 5.48): from 19
C in the north (Kherson) and 12
C at Sulina and Constanţa to 2
C in the south and east (Trabzon and Batumi).

166

5

The Black Sea Basin’s Meteo-Climatic Characterization

Table 5.14 Annual mean sea level pressure on the Black Sea coast (1974–2013) Port Sulina Constanţa Varna Burgas Istanbul Airport Zonguldak Samsun Trabzon Batumi Adler Tuapse Kerch Yalta Chornomorsk Kherson Odesa

Annual mean sea level pressure (hPa) 1016 1016 1017 1017 1016 1016 1017 1017 1016 1016 1016 1016 1016 1017 1016 1017

Period years 1984–2006 1984–2013 1974–2013 1974–2013 1974–2013 1984–2013 1984–2001 1984–2013 1984–2001 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013

1017 1016,5 1016 1015,5 1015

Annual mean sea level pressure on the Black Sea coast Fig. 5.44 Annual mean sea level pressure on the Black Sea coast (1974–2013)

– The period maximum temperature (Table 5.17 and Fig. 5.49): from 34
C in the northwestern part (Sulina) to 46
C in the north (Kerch). – The period minimum temperature (Table 5.15 and Fig. 5.50): from 6
C in the south (Trabzon) to 26
C in the north (Trabzon). – The precipitation regime (Fig. 5.51): the highest amounts of precipitation are in Batumi (234 mm in January, 168 mm in July, 297 mm in November), and in Zonguldak (137 mm in January, July 80 mm, 142 mm November); the lowest amount of precipitation is recorded in Sulina (19 mm in January, July 26 mm, 22 mm in November) and Constanţa (30 mm in January, July 30 mm, 29 mm in November).

5.4 Black Sea’s Main Ports Meteorological Data Analysis

167

35

30

25

20

15

10

5 Ianuarie I

Batum i

Februarie II

Burgas

Martie III

IVA prilie V

MaiVI

C ons tanta

Kerch

Iunie V

VI Iulie

N ovoros s iys k

VI

A ugust VII

Odes a

Septembrie Octombrie Dec VIII IX X Noiembrie XI XIIembrie

Sam s un

Sulina

Zonguldak

Fig. 5.45 The Black Sea ports—maximum monthly temperature average 20

15

10

5

0

-5

-10

-15 Ianuarie I

B a tu m i

Februarie II

B u rg a s

Martie III

IVA prilie

C o n s ta n ta

V

Mai VI

K e rch

Iunie V

VIIulie

N o vo ro s s iys k

t Septembrie Oc tombrie Noiembrie embrie VI A ugusVII VIII IX X XI DecXII

Od e s a

Sam s un

S u lin a

Zo n g u ld a k

Fig. 5.46 The Black Sea coast—minimum monthly temperature average

– The wind regime: in January the highest values of wind’s speed are recorded in Sulina and Batumi 13 m/s, and the smallest ones in Samsun and Zonguldak 5–6 m/s; the maximum values recorded in May are 12 m/s in Sulina, 9 m/s in Kerch and Novorossiysk, 3–4 m/s in Samsun and Zonguldak; in July the wind speeds are lower: 11 m/s in Sulina, 9 m/s in Kerch, 3–4 m/s in Samsun and Zonguldak; in November the medium wind speed at Samsun and Zonguldak is recorded; it can be noticed that the highest wind speeds are recorded in Sulina (all over the year), and the lowest in Sulina and Zonguldak; average wind speed values are between 3–14 m/s, higher during winter in the north-west sector of the Black Sea and lowest in the southern part of the sea during summer (Fig. 5.50). – The storm regime: days with gales (generally very few stormy days, except for ports of Sulina, Adler, Kerch, Sulina si Tuapse); days with thunder, from six days (Adler) to 28 (Batumi) and 34 (Tuapse), (Table 5.16 and Fig. 5.50).

168

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The Black Sea Basin’s Meteo-Climatic Characterization

Table 5.15 Temperatures on the Black Sea coast (1974–2013)

Port Sulina

Annual mean maximum temperature (. . .
C) 30

Annual mean minimum temperature (. . .
C) 12

Period maximum temperature (. . .
C) 34

Period minimum temperature (. . .
C) 20

Constanţa

33

12

38

18

Varna

34

11

40

18

Burgas

35

10

43

15

Istanbul Airport Zonguldak

35

4

40

9

33

4

40

7

Samsun

32

4

39

6

Trabzon

32

2

40

6

Batumi

33

2

38

8

Adler

33

6

39

11

Tuapse

34

9

38

17

Kerch

34

14

46

21

Yalta

32

6

39

13

Chornomorsk

35

14

42

23

Kherson

36

19

41

26

Odesa

34

15

43

24

Period years 1984– 2006 1984– 2013 1974– 2013 1974– 2013 1974– 2013 1984– 2013 1984– 2001 1984– 2013 1984– 2001 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013 1984– 2013

– In winter gales are experienced over the open sea throughout the entire region and winds of the force of 8 or more are recorded about 10% of occasions of west coasts and on around 5% of occasions elsewhere. Winds of force 9–10 have been recorded in most areas and force 12 has been recorded on the west coast and near Novorossiysk. Most gales are from NE, but occasionally S or SE [7]. – The Black Sea coast fog regime can be characterized as follows: the number of foggy days during summer is 0–3 and 1–7 days during winter; during summer the average number of foggy days is 0–3 and during the winter between 1–7 days; in January, 7 days with fog are recorded in Constanța and Odesa, 5 days in Kerch, a

5.4 Black Sea’s Main Ports Meteorological Data Analysis

169

50 40 30 20 10 0 -10 -20 -30 Mean annual maximum temperature Period maximum temperature

Mean annual minimum temperature Period minimum temperature

Fig. 5.47 Black Sea coast – mean annual minimum and maximum average Table 5.16 Days with gales and thunder on the Black Sea Coast Port Sulina Constanţa Varna Burgas Istanbul Airport Zonguldak Samsun Trabzon Batumi Adler Tuapse Kerch Yalta Chornomorsk Kherson Odesa Average

Days with gales 21 1 7 10 2 1 1 – 2 33 11 34 1 4 1 2 8.7 days/year

Days with thunder 14 18 18 14 14 24 16 23 28 6 34 14 24 17 15 19 days/year

Period years 1984–2006 1984–2013 1974–2013 1974–2013 1974–2013 1984–2013 1984–2001 1984–2013 1984–2001 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013

day in Batumi; in May, there are 4 foggy days in Zonguldak, 3 days in Constanța, Odesa, and Novorossiysk, and one day in Batumi; July is a month with almost no fog (one day in Constanța, Odesa and Novorossiysk); in November, an average of 5 days of fog is recorded in Constanța and Odesa, 4 days in Kerch, 0 in Batumi (Fig. 5.51).

170

5

The Black Sea Basin’s Meteo-Climatic Characterization

20

15

10

5

0

-5

-10

-15 IanuarieI

Februarie II

Batumi

Martie III

Burgas

IVAprilie

V

Constanta

Mai VI

Kerch

Iunie V

VIIulie

VI AugustVII Septembrie VIII

Novorossiysk

Odesa

Octombrie IX

Samsun

Noiembrie X XI

Sulina

Decembrie XII

Zonguldak

Fig. 5.48 Black Sea ports—precipitation monthly average 14 12 10 8 6 4 2 0 Ianuarie

Februarie

I

II

Batumi

Burgas

Martie

III

Aprilie

IV

Constanta

Mai

V

Iunie

VI

Kerch

V

Iulie

VI

Novorossiysk

August

VI

VII

Odesa

Septembrie

VIII

Samsun

Fig. 5.49 Black Sea coast—the wind regime 40 30 20 10 0

Days with gales

Fig. 5.50 Black Sea coast – storm regime

Days with thunder

Octombrie

IX

Noiembrie

X

Sulina

XI

Decembrie

XII

Zonguldak

5.5 Conclusions

171

9 8 7 6 5 4 3 2 1 0 Ianuarie

I

Februarie

II

Batumi

Martie

III

Burgas

Aprilie

IV

Constanta

V

Mai

VI

Iunie

V

Kerch

Iulie

VI

Novorossiysk

VI

August

VII

Odesa

Septembrie

VIII

Octombrie

IX

Samsun

X

Noiembrie

XI

Sulina

Decembrie

XII

Zonguldak

Fig. 5.51 The Black Sea ports—fog regime

5.5

Conclusions

In the Black Sea coast area, the annual average temperature is between 10 and 15.2
C, and the maximum temperatures generally vary within limits 40
C to +40
C. In the Black Sea basin, the annual average pressure is approximately 1016–1018 Mb, having extreme values in July–August (i.e., 1011–1014 mb) and in January (1018–1025 mb). The pressure distribution at a given moment in the Black Sea area differs very much from the average pressure distribution for that period. There are 14 types of baric fields more frequently acting on the Black Sea, out of which the most important for the winds' formation over the Black Sea being as follows: the weak gradient, the weak wind (2m/s), the cyclone in the eastern sea part, the southern edge of the cyclone, the cyclone northern edge, the eastern edge of the cyclone, the eastern edge of the anticyclone, and the southern part of the anticyclone. The main types of pressure systems that act in the Black Sea are cyclone, anticyclone, ridge of high pressure, a trough of low pressure. The Black Sea winds’ regime can be characterized as follows: the winds dominance depends on the region, the winds from the north-west, north, and north-east are met on the north-west shores with a probability of 50%; during the spring time, the north-west and north-east winds are prevailing; during the winter time, on the western shore of the Crimean Peninsula, the wind from the north-east is prevailing (30–40%), during the spring time, the south wind (20–25%), and during the summer time, the winds from the north-west (25–30%) and north-east (19–20%); in the Kerch Strait area, the winds from the east and north-east prevail throughout the year (30–45%), but, also, those from west and north-west are important, too; on the Caucasian coasts, the winds from the south and south-west are prevailing at a rate of 40–55%; on the Anatolian coasts, during the cold season, the south and south-east winds are prevailing, as well as the north-west and north-east, as squalls, and during the summer season, the winds are weak and moderate from all directions; during the spring and autumn seasons, they have unstable directions.

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The Black Sea Basin’s Meteo-Climatic Characterization

The annual wind speed average does not exceed 7 m/s in the coastal areas, the multiannual maximum being recorded at the river mouths of the Danube Delta, at Cape Tarkhankut, the Kerch Strait, nearby Novorossiysk, the Romanian and Bulgarian coast, and the minimum wind speed being recorded in the area of the mountainous coast. Generally, the strong winds' direction coincides with the direction of the prevailing winds; the windy days’ average is 38 days in Odesa, 44 days in Sevastopol, 29 days in Kerch, 55 days in Novorossiysk, 20 days in Batumi, less than 27 days in Trabzon, Samsun, and Eregli. The maximum wind speed was recorded in the Tendre’s tongue area (41 m/s, respectively), and in Sevastopol, Novorossiysk, Tuapse, Poti, Batumi, Sinope, Eregli, Constanţa, Varna areas, as well. The most intense storms with waves estimated as 7.8 m in height and a period of 11.0 s have been recorded in the western and north-eastern parts of the Black Sea, with a return period of 100 years, maximal possible height being over 14 m. Over 50% of storm events identified are the consequence of "coupling" of a continental anticyclone with a Mediterranean cyclone arriving over the Black Sea. Extreme storms in the north-west region have a mean recurrence rate of 7 years. For the Black Sea basin, the relative humidity average has an inverse variation to the temperature variation. The spatial distribution of the water vapors' tension has the gradient always oriented towards the sea; the relative humidity isolines are approximately parallel to the shore, having higher values towards the sea center. The annual average nebulosity in the Black Sea basin is off about 5.6 tenths. During the winter season, the nebulosity has a more homogeneous distribution than in the warm and in the transition seasons. The average nebulosity variation throughout the Black Sea is similar to the coastal nebulosity variation. The nebulosity average variation has a co-sinusoidal variation shape with maximum values in the cold season (6–8/8, respectively), and with minimum values during the summer season. The precipitation regime in the Black Sea basin is as follows: 42% of the annual rainfall is distributed during the summer season and 58% in the rest of the year; the multiannual precipitation average on the coast is superior to the value of the entire sea basin. The Black Sea coast fog regime is as follows: the number of foggy days during summer is 0–3 and 1–7 days during winter; during summer, the average number of foggy days is 0–3, and during winter between 1–7 days.

References 1. ***The Black Sea in the Romanian littoral zone, Hydrological monograph, Bucharest, (in Romanian), 1973 2. ***Romanian Black Sea Pilot Volumes 1 and 2 with amendments, EX PONTO Publishing House, Constanta, (in Romanian), 2006 3. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 3rd Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2010

References

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4. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 4th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2013 5. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 5th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2017 6. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 6th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2019 7. Boşneagu R (2004) Geographical conditions influence of the Maritime Routes in the Black Sea Basin (Western sector). Cartea Românească, Publishing House Bucharest, Romania, (in Romanian) 8. Şelariu O (1997) Elements of meteorology and marine hydrology (Elemente de meteorologie şi hidrologie maritimă). Editura Tipofin, Constanţa, (in Romanian) 9. Surkova G et al (2013) Atmospheric circulation and storm events in the Black Sea and the Caspian Sea. Open Geosciences 5(4)., accessed 10.01.2021 10. Velea L, Bojariu R, Cica R (2014) Occurrence of extreme winds over the Black Sea during January under present and near future climate. Turkish Journal of Fisheries and Aquatic Sciences 14(1–2)., accessed 10.01.2021 11. Rusu E et al (2018) A joint evaluation of wave and wind energy resources in the Black Sea based on 20-year hindcast information. Energy Exploration & Exploitation 36(2)., accessed 10.01.2021 12. Chiotoroiu BC (1998) Les tempêtes dans le bassin occidental de la mer Noire, http://www. theses.fr/1998AIX1A019 13. Galabov V, Chervenkov H (2019) Study of the Western Black Sea storms with a focus on the storms caused by cyclones of North African Origin. Meteorology and Climatology of the Mediterranean and Black Seas, Springer Link 14. Lopatoukhin L et al (2009) Statistics of Black Sea extreme storms. In Proceedings of the ninth international conference on the mediterranean coastal environment, MEDCOAST 09, E. Ozhan (ed), Sochi, Russia, accessed 15.01.2021 15. Vespremeanu-Stroe et al (2016) Project Changes in storminess and coastal erosion induced by climate variability along the Black Sea Coast. Management and adaptation – BS_STEMA, UEFISCDI, and EU under FP7 Initiative ERA.Net RUS Plus through contract nr. 42/2016, accessed 15.01.2021 16. Rusu E (2018) An analysis of the storm dynamics in the Black Sea, https://www.researchgate. net/publication/327386526_AN_ANALYSIS_OF_THE_STORM_DYNAMICS_IN_THE_ BLACK_SEA. Accessed 15.01. 2021 17. Todorova A et al (2018) The Black Sea, Chapter 8, World Seas: An Environmental Evaluation, in the book: World Seas: an environmental evaluation 2nd edition volume I: Europe, The Americas, and West Africa Publisher: Elsevier, https://www.researchgate.net/publication/ 3274 99429_Black_Sea_ Chapter_8_World_Seas_An_Environmental_Evaluation. Accessed 16.01.2021 18. Akyarli (1993) Wave Climate Studies Along the Turkish Coast of the Black Sea. In: Kosyan R (ed) Coastlines of the Black Sea. American Society of Civil Engineers, New York 19. Boşneagu R (2016) Physical – geographical conditions influence on the Black Sea climatic factors evolution. International Journal of Cross-Cultural Studies and Environmental Communication 5/2016. 20. Boşneagu R, Torică E, Torică V (2018) A first approach to the impact of the global and regional geo-climate changes on the sustainable development of Dobrogea region. In: Bologa AS (ed) Dobrogea at 140 years after its Union with the Romanian State. Ex Ponto Publishing House, Constanţa

Chapter 6

The Influence of Weather and Climate Factors on the Navigation and Seaborne Trade on the Black Sea

Abstract In the Black Sea basin, the meteorological factors influence directly and permanently the navigation and seaborne trade. Their influence materializes in hindering the navigation, increasing the voyage duration, the damage of the transported cargo, the additional energy consumption, the additional physical wear of the vessel and the installations on-board, the discomfort to the crew generated by the "seasickness," the dangers to the ship’s safety, and even loss of the crew and cargo. Under extreme weather conditions, port operations, such as ships’ handling, fishing, other maritime activities, and even navigation on the large seas, are impeded and even interrupted. Regardless of the class, size, and the nautical and constructive qualities, there are no ships that could be safeguarded against the damage caused by meteorological factors. Keywords Black Sea · Navigation · Wheather and climate factors Navigation on the Black Sea raises some specific issues that need to be considered, to ensure maximum safety conditions for the ship, crew, and cargo throughout the voyage. Under the current conditions of the global maritime market having a high degree of concurrency, respectively, the problem of reducing fuel consumption and the time needed for performing various voyages, especially in crossing the ocean on different routes, is particularly important for shipowners. The economic effect is determined by converting this time into the corresponding cost price, fuel consumption having the main percentage; to these is added the benefits increase by reducing the period of undertaking the transport contract. The problem becomes more important for large ships, where the daily fuel consumption is considerable. The excessive wear and damage of the ships’ installations, caused by their exposure to unjustified requests during voyages, and, respectively, maintaining of high speed when navigation is performed against the wind on a rough sea, etc. are causing losses due to repair costs and their immobilization to do the necessary remedies as well. These are the most important reasons, but not the only ones, that require an elaborate study of the meteorological conditions that influence navigation on the Black Sea, having unique features in the world, due to its size, and being the largest inland sea in the world, connected to the oceans only by the Bosporus Strait. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_6

175

176

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

When the economic criterion is in contradiction to that referring to safe navigation, the priority will be given to the safety criterion in choosing the sea crossing routes. Modern navigation uses means of high technical complexity, extremely expensive, but very efficient, too. The danger of the ship’s collision and grounding, with dire consequences (e.g. losses of lives, goods, the marine and coastline pollution by hydrocarbons or other harmful substances), has significantly increased as a result of the world fleet’s development, and the impressive growth of the ships’ tonnage and speed as well. The risk factors have multiplied, a fact that calls for searching measures for increasing maritime navigation safety, especially in the areas with heavy traffic. In this context, the International Convention for the Safety of Life at Sea (SOLAS) held in 1960 in London under the auspices of the International Maritime Organization, which has subsequently been revised on several occasions, proposed a system of compulsory navigation routes, as well as of separation zones of the maritime traffic. The system is designed for navigation in any weather conditions, respectively, during day or night, and in ice-free waters as well (Fig. 6.1). The effect of the weather conditions on the route and speed is specific to each ship. Moreover, the effects of these factors are different even for the same vessel, according to the draught and the trim, respectively, that are caused by the ships’ loading and position against the wind. The analysis of the climatic factors’ regime influencing the navigation and the maritime transport in the Black Sea basin shows that: – The winds (Figs. 6.2, 6.3, 6.4, and 6.5) and the most dangerous storms for navigation occur during the winter season, when the north and north-east winds

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA NOVOROSIYSK

SEVASTOPOL YALTA MIDIA

TUAPSE CONSTANŢA SOCHI

MANGALIA

ADLER

VARNA

SOCHUMI KULEVI TERMINAL

BURGAS

POTI

INEBOLU

SUPSA TERMINAL BATUMI

SINOP

AMASRA

ISTANBUL

HOPA

ZONGULDAK EREGLI

SAMSUN

RIZE

FATSA GIRESUN

Fig. 6.1 The Black Sea—maritime traffic separation schemes

TRABZON

6 The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

177

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA

NOVOROSIYSK YALTA

CONSTANŢA

TUAPSE

ADLER

5

VARNA

5

10 5

BURGAS

15

20 25

ISTANBUL AIRPORT

ZONGULDAK

BATUMI

SAMSUN TRABZON

Fig. 6.2 Black Sea—percentage frequency of winds force 7 or over, February. (Source: Compilation after [1–5])

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA

NOVOROSIYSK YALTA

CONSTANŢA

4

TUAPSE

ADLER VARNA

BURGAS

2 2

4 2 4

ISTANBUL AIRPORT

BATUMI ZONGULDAK

SAMSUN TRABZON

Fig. 6.3 Black Sea—percentage frequency of winds Beaufort force 7 or over, May. (Source: Compilation after [1–5])

178

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

6

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA

NOVOROSIYSK YALTA

CONSTANŢA

4

TUAPSE

4 2

ADLER

VARNA

2 BURGAS

ISTANBUL AIRPORT

4

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 6.4 Black Sea—percentage frequency of winds Beaufort force 7 or over, August. (Source: Compilation after [1–5])

Black Sea KHERSON ODESA

15

CHORNOMORS’KE KERCH

SULINA

10 NOVOROSIYSK YALTA

5

CONSTANŢA

10 VARNA

TUAPSE

ADLER

15 5

BURGAS

10

5 ISTANBUL AIRPORT

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 6.5 Black Sea – percentage frequency of winds Beaufort force 7 or over – November. (Source: Compilation after [1–5])

6 The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

– – – – – – –

–

–

–

179

prevail (the south-west and the west winds in the south-eastern part occur frequently), having a 3–8 m/s speed; the number of stormy days is 3–8 per month (i.e., representing 10–28%), lasting more than during the warm season (i.e., up to 17 per season); they have a significant influence on the transport by drifting the ship, thus being necessary for the ship to look for shelter in special situations, also by inducing unwanted oscillations that become dangerous for the ship; the damage caused by the storms’ action to the ships and the Romanian coast is particularly strong. The wind is acting on the ship’s sail area, influencing the ship’s steering (i.e. it helps or it restrains the maneuver) and its stability, having adverse effects on the ship’s safety. The streamline resistance due to the air is given by the horizontal component of the aerodynamic forces’ resultant, forces exerted on the hull’s emerged surface, and it occurs both during navigation and on calm or windy weather. During the spring season, storms from west and north-west may occur, accompanied by unstable and cloudy weather. During the summer season, the winds are more unstable, generally having small speeds, i.e., of 2–5 m/s, with no particular influence on navigation; During the autumn season, the winds are unstable, windless days are rare, with a frequency not exceeding 4–7%. The average annual number of days with thunderstorms is 25–45, which means the activity is diminished by a percentage of 5–12%; The local winds’ presence has a special influence on navigation, especially in the areas having high coasts, i.e., from the east part of the sea; they become dangerous as a result of their high speeds reached in a very short time, also large coastal waves, accompanied by lower temperatures and iced sea (e.g., “Bora,” in the area between Anapa and Tuapse). The extreme air temperatures (the negative ones, with the isolated character in the north part, i.e., of
25 to
27 , and the positive ones, i.e., higher than 37 ) are influencing by reducing the time for loading and unloading operations in the ports, and the work on the ship’s deck, too; it must be noted that the negative temperatures are especially in conjunction with the northern and north-eastern winds and they do not last for a long time; during the winter season, the temperature average varies between
2 in the northern sector and 9 in the southern sector, meaning that, in general, the temperature conditions are appropriate for undertaking maritime activities; during the summer season, the monthly average temperature is between 20 –24 in the entire sea basin, thus providing a good climate for navigation and seaborne trade. The air humidity has a significant influence on carried goods by degrading those that are sensitive to its action, but also on the ship, through the rust phenomenon; during a year, the relative air humidity value varies between 70–85%, rarely exceeding the higher values, creating the so-called thermal discomfort. The fog, an undesirable phenomenon, with a negative impact on navigation, that causes naval accidents, interruption of the port’s activities, etc., is formed on the open sea during calm weather; also, at the seaside, the foggy days’ average varies from 24 to 42 days on the western coast, 3 to 27 days in the east, 7 to 11 days in

180

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

Table 6.1 Black Sea’s main ports—days with fog

Port Sulina Constanţa Varna Burgas Istanbul Airport Zonguldak Samsun Trabzon Batumi Adler Tuapse Kerch Yalta Chornomorsk Kherson Odesa Average

Days with fog 21 32 16 24 11 16 8 7 3 10 4 27 8 21 42 36 17.8

Period years 1984–2006 1984–2013 1974–2013 1974–2013 1974–2013 1984–2013 1984–2001 1984–2013 1984–2001 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013 1984–2013

40 35 30 25 20 15 10 5 0

Days with fog

Fig. 6.6 Black Sea’s main ports—days with fog

the south—average days per year (Table 6.1 and Figs. 6.6, 6.7, 6.8, 6.9, 6.10, and 6.11). – The visibility has particular importance on maritime navigation, making it difficult up to impeding it, i.e., during summer it is very good, but it gradually decreases up to zero; during the wintertime, respectively, it falls due to the relatively high air humidity and increased precipitation quantities; the daily regime of visibility is the following: it is reduced in the morning, the highest values occur during the daylight; also, it must be mentioned that the visibility is low during the spring season (i.e., up to 5 nautical miles) due to the presence of the fog;

6 The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

181

KHERSON 36

42 CHORNOMORS’KE 21

21

27 YALTA 8

32

4

ADLER

Average 17.8 days with fog per year

VARNA

TUAPSE

10

16 24

16

3

11

11 ISTANBUL AIRPORT

7 TRABZON

Fig. 6.7 Black Sea’s main ports—days with fog

KHERSON

4

CHORNOMORS’KE

YALTA TUAPSE

2

ADLER VARNA

2 4

6

2

ISTANBUL AIRPORT TRABZON

Fig. 6.8 Black Sea—percentage frequency of fog, February. (Source: Compilation after [1–5])

182

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA NOVOROSIYSK

YALTA CONSTANŢA

TUAPSE

2

ADLER

2 VARNA

BURGAS 4

ISTANBUL AIRPORT

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 6.9 Black Sea—percentage frequency of fog, May. (Source: Compilation after [1–5])

Black Sea KHERSON ODESA

CHORNOMORS’KE KERCH SULINA NOVOROSIYSK

YALTA CONSTANŢA

2

TUAPSE ADLER

VARNA

0 to 1

BURGAS

ISTANBUL AIRPORT

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 6.10 Black Sea—percentage frequency of fog, August. (Source: Compilation after [1–5])

6 The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

183

Black Sea KHERSON ODESA 6 4

CHORNOMORS’KE KERCH

2 SULINA

NOVOROSIYSK

YALTA CONSTANŢA

TUAPSE ADLER

VARNA 4 BURGAS

ISTANBUL AIRPORT

2

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 6.11 Black Sea—percentage frequency of fog, November. (Source: Compilation after [1–5])

– The nebulosity directly affects the possibility of celestial observations in order to determine the ship’s position; the annual nebulosity average is of the sixth degree, having a maximum value during wintertime and a minimum value during summertime. – Also, the precipitations have a negative effect on the transported goods and especially on those shipped on the deck, such as timber, the machinery, the parts of and oversized equipment, live animals, etc.; they have an uneven distribution in the Black Sea basin, the lowest value being recorded on the western coast (i.e., 300–500 nautical miles) and the highest value on the eastern coast (i.e., 1500–2500 mm). During the summer season, the rainfalls have a torrential character, and during wintertime, the precipitations are formed by rainfalls and snowfalls (during rainfalls and heavy snowfalls, port activities are disrupted and navigation becomes quite difficult). It is important to know that the dangers for navigation, the shallow waters, the rocks, the wrecks, and the obstructions occur particularly along the coast. Therefore, the importance of the hydro-meteorological conditions increases, as well as the attention and need for precision, to ensure efficient coastal navigation. Certainly, in the same area, the coastal navigation requirements increase significantly, i.e., in the conditions of low visibility and a disturbed sea. The prevailing winds from the western basin of the Black Sea are those from the north-west, north, and east (during the winter season, the predominance represents over 50%), while during the summer season, the winds from the north-west prevail (the predominance representing 20–30%). This fact means that, for a significant

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period, the wind that generally blows from the northern sector will enhance the action of the marine currents from this area, thus,, the leeway (i.e., as a result of the combined effect of the wind and the sea currents) will affect the coastal navigation, especially for the small- and medium-sized ships, the ships “at anchor”, respectively (on the Romanian Black Sea coast, several ship grounding incidents have occurred, out of which there were some cases with tragic consequences, resulting in loss of ships and casualties, during some severe storms that caused particularly large waves). The fog is particularly present in the north-west and north sector, i.e., over 40 days/year; a considerable presence of the fog is reported from September to March in the N-W (i.e., 5–9 days/month); 3–4 days/month on the entire western coast of the Black Sea, representing a considerable period with negative influences on the navigation; in the eastern part, the days with fog are about 15–20 per year; and in the south, there are 3–15 days per year. The quantity of precipitations in the western part is about 200–700 mm per year, however considerably lower than in the eastern Black Sea basin, varying from 219 mm in the north-western sector (Sulina) to 86–105 mm on the entire western coast in the summertime, to 90–110 mm during springtime, and 53–74 mm during wintertime. In the eastern part, the quantity of precipitations is from about 600 mm per year to over 2000 mm per year, and in the south, it is about 600 mm per year to over 1200 mm per year (Zonguldak).

6.1

Conclusions

In the Black Sea basin, meteorological factors influence directly and permanently navigation and seaborne trade. Their influence materializes in hindering the navigation in the following ways: increased voyage duration, damage to the transported cargo, additional energy consumption, additional physical wear of the vessel and installations on-board, discomfort to the crew generated by the “seasickness,” dangers to the ship’s safety, and even loss of crew and cargo [6]. Under extreme weather conditions, port operations such as ships’ handling, fishing, other maritime activities, and even navigation on the large seas are impeded and even interrupted. Regardless of the class, size, and the nautical and constructive qualities, there are no ships that could be safeguarded against the damage caused by meteorological factors. The knowledge of the meteorological factors’ influence on the ship and navigation is important and required for the crew’s training to achieve an optimal balance between safety and economic efficiency, as well as to choose the best, safest, and most economical route, under the conditions of preparing the ship and the crew for bad weather conditions. The atmospheric pressure does not influence directly navigation, but its variation has implications on the movements of air masses, and it portends the weather evolution as well. The wind has a great influence on navigation, having an important role in waves’ formation, sea-level oscillations, etc.

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185

The wind produces the ship’s drifting from the established route, a phenomenon called leeway, the decrease of the ship’s speed, and the ship’s transversal inclination as well. The characteristic regime (positive) of the air temperature in the Black Sea basin (i.e., on the coast, in ports, and offshore) has throughout the year a favorable influence on navigation, only the periods of extremely negative and negative temperatures restrain this activity. The air temperature influences the crew’s works (i.e., when the temperatures are low or high, and also, it influences the transported goods). Different categories of transported goods (e.g., bulk goods, chemical goods, and frozen and chilled food products) have restrictions regarding the temperature conditions during shipping; generally, the air temperature increasing over the limit causes deterioration of parts of the transported goods or of the whole freight. The relative humidity is 70–80%, and it affects human activities during the voyage and port operations; also, it can cause damage to the transported cargo, i.e., by rust, rot, etc., processes that require continuous and controlled ventilation of the cargo hold. The nebulosity regime in the Black Sea basin is favorable for navigation and maritime transportation throughout the year, except for some periods (not too long), during the winter season. The precipitation regime does not have an unfavorable effect on navigation in the Black Sea basin. The strong precipitation that affects especially the port loading and unloading operations is short, particularly in the western basin of the Black Sea. Good visibility is characteristic to the Black Sea area in a proportion of 63%; thus, navigation is favored throughout the year, except for some unfavorable periods (hours and, rarely, days), especially during the weather transition seasons. The fog factor, a phenomenon of special importance in navigation (similarly to visibility), is formed on the sea during the transition from winter to summer, and during the reverse passing, it is formed at the seashore; the evaporation fog is formed over the Black Sea during the transitional and the cold seasons; the advection fog is formed at the seashore (in the conditions of a weak air movement and an evident nighttime cooling). The maximum number of days with fog at the seashore and offshore (during winter or summer) is small. Therefore, it does not have a strong influence on navigation neither on maritime transport in the Black Sea. Due to the weak convective air movement above the Black Sea basin, the appearance of electrical phenomena is low, too. The thunderstorms occur between May and September (1–7 days/month). The waterspouts occur above the sea (i.e., at the appearance of the Cumulus clouds) during the summer and early autumn. Thus, the number of days with hail is 1–2 per year, particularly in April and May. The speed of sound inside the seawater depends on the temperature and the water density, and it has direct implications in hydro-acoustics, used for: underwater targets finding for submarines and ocean fishing. Due to its chemical composition, seawater is a strong corrosive agent for the ship’s hull and other hydro-technical structures. To obtain a maximum speed value and safety (and also, to reduce the possible damage), the optimization between the ship’s movement and the marine

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environment supposes the knowledge of the ship’s motion characteristics for different draughts and trims, under different sea conditions. The necessary information for such a “maneuver” is that referring to the ship (the displacement, the draught, the stability, the speed over the sea bottom, the size of the ships’ oscillations), as well as those referring to the sea (i.e. the direction and the force of the wind, the height and the period of the wave, the wind’s action time). By statistical processing, some diagrams show the effect of the weather on the ship, i.e. in particular loading situations and voyage. These characteristic curves can be represented for the following standard situations: the empty ship, ship in ballast, fully loaded ship, and for some different conditions of loading, other than the standard ones. These items of information are important to emphasize how the sea state imposes or not the ships’ speed decrease. Therefore, two cases will be considered: at a required operation speed, this will decrease with the worsening weather, and in the conditions of a certain sea state as well, when the ships oscillations may become violent, a fact that will impose the deliberate reduction of the speed, thus ship steering becoming easier (the results consisting of the reduction of the efforts in the hull, into the propulsion and steering systems). These characteristic curves, called the ship’s “behavior,” which are simultaneously used with the meteorological, navigation, and recommended routes charts, will be useful in determining the speed. The speed has the best response in certain navigation situations.

6.2

Short History of the Black Sea’s Storms

Although, fortunately, strong storms, relatively rare in the Black Sea, are violent, usually short-lived, compared to the oceanic ones, which are particularly destructive. The history of catastrophic storms in the modern history of the Black Sea begins with the terrible storm of November 14, 1854, called Balaklava Gale. This storm, with a speed of about 30 km/h, a radius of 90 nautical miles, with a maximum speed of over 35 m/s, led to the sinking of 30–34 English, French, and other warships (Fig. 6.12), as well as the loss of nearly 1500 sailors. The storm on January 28–29, 1968 was also considered to be among the strongest on the Eastern Black Sea by its intensity, duration, coverage area, and consequences. That outbreak of cyclonic activity over the Black Sea followed on a build-up of a deep stationary cyclone (985 hPa in the center) between two anticyclones – a warm one in the south-east (over the Caucasus) and a cold one in the north-west of Europe. That secondary cyclone crossed the Turkish Anatolia coast at a speed of 50 km/h and reached the Kerch Strait on January 28, 1968. During the night of January 27–28, the wind velocity had sharply increased and the westerly near the Turkish coast reached 30–34 m/s with a windy zone exceeding 100 km in radius. Following the cyclone trajectory, the zone jointly with the hurricane winds moved towards the Kerch Strait extending to the whole Black Sea. The winds blew at a speed of 20–30 m/s in the Black Sea interior and up to 35 m/s by the Crimean Peninsula. The maximum wind speed (30–34 m/s) zone reached the Caucasian coast by the evening of January 28.

6.2 Short History of the Black Sea’s Storms

187

Fig. 6.12 The gale off the port of Balaklava, 14th Nov.1854/W. Simpson del.; R. Carrick lith. (Source: Public picture from https://www.loc.gov/pictures/item/2004672563/ [7])

That storm was unusual due to the occurrence of long waves, which caused a 1.5-m sea-level rise at the Caucasian coast, and 9–10 m wind waves that crashed at the Sochi pier producing the 30–40 m high splashes. As their result, the coastal railway and houses were over flooded [8]. The storm on February 1979 (named the Bulgarian storm of the century). During the storm, the sea level in the tide gauge station at Irakli beach reached 1.43 above the mean. The data from the measurements in Varna and Burgas are not available, due to the fact that the mareograph equipment wasn’t designed to measure sea level values of more than 1.5m and they have been flooded and damaged. The significant wave height near the village of Shkorpilovtsi reached at least 5.8m at 15m depth, and it is not clear if that is the maximum, due to the fact that the storm destroyed the wave measurement equipment and the pier with the other measurement equipment [9]. The storm on January 1981 caused significant damage to the Tomis marina located north of the port of Constanta (Fig. 6.13) [6]. The storm on November12–16, 1981 was a similar storm brought by a Southern cyclone, though accompanied by a smaller decrease in the atmospheric pressure. During that storm, the cyclone center stayed over Crimea for three days. The isobars and its followed geotropic wind flow on the Eastern storm periphery rushed to the Kerch Strait in parallel to the Caucasus Mountains. The wind reached its maximum over the North-Eastern Black Sea [8]. The storm on January 1995, with an average duration of 50 h, produced the greatest peacetime disaster in the history of navigation on the Romanian Black Sea coast. On January 4, at 00.00 UTC, at ground level, the depression centered in

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Fig. 6.13 Damage caused by the January 1981 storm in the Tomis Marina [6]

southern Italy. The pressure at the center is 1000–1005 hPa, and its area of influence covers the southern Balkans and the Western Black Sea. Western and north-east Europe were under the influence of the rather intense anticyclone (up to 1035 hPa). On January 5, at 00.00 UTC, the depression was still centered in southern Italy, but the anticyclone shifted eastward, strengthening (1040 hPa). At the Gloria meto station from January 3, 08.00 to January 5, 20.00 can be observed a significant decrease in air temperature by more than 4.5  C in 30 h (from 5  C to 6  C on January 4 at 02.00, at 1.5  C in Gloria, 0.4  C in Sulina, and 0  C in Constanţa on January 05 at 08.00); a slight but steady increase in atmospheric pressure from 1011 hPa on January 3 to 1023 hPa on January 5, so an increase of 12 hPa in 48 h; a wind rotation from NW to NE, from January 3 at 14.00, on January 5 at 20.00; a wind strengthening of January 3 at 20.00, with a maximum on January 4, after 20.00, when it reached a speed of 25–26 m/s (average speed over two minutes) and 30–32 m/s, in bursts at Gloria and Sulina; an evolution of the wave height that closely follows the increase of the wind intensity, this phenomenon being favored by the closed sea character of the Black Sea (the values of the wave heights registered after

6.2 Short History of the Black Sea’s Storms

189

the visual observations at the Gloria Offshore Platform were higher than 9 m. Taking into account the subjectivity of these observations, a wave height of more than 8 m was considered at the peak of the storm. Following these warnings, between 08.00–14.00 (local time), most ships left Constanţa roadstep. Three ships remained anchored: “Paris” (bulk carrier of 25,957 dwt, under the Maltese flag, with a crew of 27 sailors, arrived from Greece to load 25,000 tons of chemical fertilizers), “You Xiu” (bulk carrier of 26,802 dwt, under Hong Kong flag, with a crew of 27 sailors, came from Italy to load 20,000 tons of chemical fertilizers) and “Sea Bulk Hope.” The latter hardly managed, after 16 h, to move away from the northern dam of the port, to which it was drifting. The M/V “Paris,” which had received the consent of the port captain to enter the inner harbor to get fuel, gave up making this maneuver, announcing damage to the engine, which were being repaired and its intention to remain at anchor until the next day. Despite the strengthening of the wind, the rough sea, and the repeated recommendations of the Constanţa Port Control, to enter the harbor or go to the high sea, the two ships “Paris” and “You Xiu” were still at anchor at 18.00, at 3.5 miles and 1.9 miles NE of the extremity of the northern dam of the port of Constanţa, respectively. After 18 h, the Constanţa Port Control finds the change of the position of the two ships and their drift towards the outer northern breakwaters of the port. The drift occurred to the SW, according to the direction of the wind and the waves. After hitting the dam, causing two breaches in it, the two ships began to sink. Despite the efforts of the Search and Rescue forces, it very quickly reached the site of the shipwreck and despite the forces deployed in the following days, no survivors were found. The causes of the collision of the two ships with the northern breakwaters of the port of Constanţa and the shipwreck could be the indecision in front of the storm warnings and the erroneous assessment of the technical condition of the ships. There were 54 dead and only 17 bodies recovered [6]. The storm on February 2003 was short, but the significant wave height reached the extreme value of nearly 7m [9]. The storm on November 10 and 11, 2007, a strong storm in the Kerch Strait. The northern, north-eastern, eastern, and southern winds prevail in the near-Kerch area of the Black Sea. Dangerous for navigation, coastal and off-shore hydro-technical constructions, the North-Eastern and Eastern hurricane winds have an average velocity of 30 m/s, while their gusts exceed 35 m/s. However, the Southern, South-Western, and South-Eastern winds could generate extreme waves, provided a larger distance for their formation is available. These winds do not happen often but possess a stronger destructive potential notorious for bringing natural disasters resulting from the atmospheric circulation in the Kerch area. Extremely severe conditions totaling 9 h lasted from 5:00 AM till 2:00 PM on November 11. Winds exceeding 30 m/s produced over 4 meter-high waves in the waters where the depth varied from 7 to 12 m only. In the evening of November 11, the wind went down in Sochi (2–5 m/s from the Northern bearings), while a high velocity of the SouthWestern wind continued in the Northern part of the water space reaching 5–15 m/s at the Tuapse-Gelendzhik section and 15–25 m/s around Anapa. In the meantime, the sea storm was increasing, and during the night of 11 to 12 November, the height of

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the South-Western and Western waves reached 3.0–3.2 meters at the Sochi coast and 5.0 and 4.0 meters, accordingly, at the Tuapse and Gelendzhik coasts. At 18:00 GMT on November 11, 2007, for the first time in the history of observations carried out in the Sochi section, a wave period of 14.8 s. was recorded, while the wavelength at the coast was registered as standing at 106 meters (at the depth of 5.0–5.5 meters). The storm maximum development phase was characterized by activation of the longwave dynamics in the sea coastal zone. Thus, based on the registrations made by a depth-gauge installed at the open sea in Sochi, the amplitude growth of the infragravitation (long-period) waves started in the day time of 11 November from 10–15 cm to reach by the evening (18:00–20:00 GMT) the height of 35–45 cm. At the same time, the infra-gravitation wave period went down from 10–12 to 3 minutes. According to the depth-gauge observations taken in Tuapse, the amplitude growth of the infra-gravitation waves in the sea-port water space was observed as well during the day time of 11 November to reach its maximum level (40–50 cm) at 14:00–17:00 GMT. The storm during the night of 11–12 November was accompanied by the sea level rise of up to 20–30 cm. The picks of the sea level rise at the long-wave rest reached 510–520 cm above the sea level in Sochi and 505–510 cm in Tuapse. The vessels that were at the Southern end of the strait within the zone of the raid load-unload regions were caught in an extremely difficult situation. The waves reaching 5.4 m height and arriving from the Black Sea were taking tankers and dry-cargo carriers away from their anchors to wash them aground at the Kerch and Taman peninsulas. In total, thirteen boats suffered an accident as a result of the storm, and of them four dry-cargo carriers and one tanker sank. The Vologoneft-139 motor tanker and the Volnogorsk, Nakhichevan, and Kovel dry-cargo motor vessels anchored in the Kerch Strait were virtually torn apart by the storm. The Volgoneft139 boat broke into two, and the bow sank in the vicinity of the main ship channel of the Strait at the 10 m depth. The other motor vessels of Volnogorsk (loaded with 2437 t of granulated sulfur), Nakhichevan (2366 t) and Kovel (1923 t) did not sink immediately but drifted towards the coast of Ukraine to the South from the Tuzla Island. It was later reported that the sulfur granulates discharged to the seafloor had been leaked from the Kovel motor vessel [8]. The accident became considered an ecological catastrophe, one of the worst in the region and the gravest since the early 1990s [10] (Fig. 6.14). The storm on February 06–08, 2012. The satellite altimetry data and the visual observations by the coastal meteorological stations show that the significant wave height reached 5m at the southern Bulgarian coast near the town of Ahtopol, where the storm caused significant damages [9]. The storm on April 19, 2017. As the storm was tracking from the Black Sea into southeastern Russia, sustained winds averaged 24 to 42 km/h, consistently for about 12 h at Rostov-on-Don, located inland from Azov. Sustained winds, however, peaked at nearly 54 km/h (33 mph) at 11 a.m. with gusts to 70 km/h. Similar winds were recorded at the coastal town of Anapa, Russia, located closer to the Kerch Strait. A cargo ship carrying grain from southern Russia to Turkey capsized amid this storm. Only one of the 12 people aboard has been rescued so far [11].

6.2 Short History of the Black Sea’s Storms

191

Fig. 6.14 Parts of the Volgoneft-139 tanker: the grounded stern, towed to Port Caucasus on November 15, 2007, and the bow removed on August 13, 2008. Public picture from Kerch Report [8]

6.2.1

The Storm on February 5–6, 2020

A short analysis of this storm is as follows: (a) February 5, 2020, Croatia Meteo warning: Violent windstorm with locally hurricane-force wind. In the wake of the intense upper-core moving over the Balkans, a very sharp pressure gradient has developed across the Western Balkans, as a strong ridge is also placed across Western Europe. This is already resulting in extremely severe winds with gusts above 150 km/h locally along the Adriatic coast, but conditions will significantly worsen tonight—peak gusts are likely to push above 200 km/h in some locations! Tonight’s pattern over Europe indicates an extensive upper-level ridge across Western Europe with a deep cold-core low over the southern Balkans, with a powerful north-northeasterly flow in between. The strong surface pressure gradient between these two systems will result in a violent windstorm (Fig. 6.15) [12]. The main data and meteorological chart explaining this storm evolution are presented below:

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Fig. 6.15 Mean sea level pressure and anomaly (hPa), February 5, 2020, 18.00 UTC

(b) Turkish State Meteorological Service Daily Marine Forecast Report, February 5, 2020, 18.00 [13]: 5 February 2020 Wednesday 18:00-18:00 Local, 15:00-15:00 UTC At 1200 GMT, there is a 984 hPa low-pressure center with a frontal system over North Aegean. This system is declining and moving to the east. East 18:00–00:00 L 00:00–06:00 L 06:00–12:00 L 12:00–18:00 L Black Sea (HopaSinop) Gale Near gale Near gale Gale warning Strong gale warning warning warning Weather Overcast Overcast Overcast, rainy Overcast, rainy in West in West Wind South and South and South and West and Southeast 5 to Southeast 5 to Southwest 6 to Southwest 7 to 7, 7, Northwest 8, Northwest 9, Northwest 5 to 7 in West 5 to 7 in West 6 to 8 in West Wave 2.0 to 3.0m 2.0 to 3.0m., 3.0 to 4.0m 4.0 to 5.0m Visibility Good Good Moderate, weak Weak at precipitation West 18:00–00:00 L 00:00–06:00 L 06:00–12:00 L 12:00–18:00 L Black

6.2 Short History of the Black Sea’s Storms

Sea (Sinopİğneada) Gale Weather Wind

Wave Visibility

Near Gale Warning Rainy West and Northwest 5 to 7, Southeast 4 to 6 in East 2.0 to 3.0m Good, moderate at precipitation

193

Gale Warning

Gale Warning

Rainy North and Northwest 6 to 8, Southwest 5 to 7 in East 3.0 to 4.0m Moderate, weak at precipitation

Rainy North and Northwest 6 to 8, Southwest 6 to 8 in East 3.0 to 4.0m Moderate, weak at precipitation

Strong Gale Warning Rainy North and Northwest 6 to 8, West 7 to 9 in East 4.0 to 5.0m Weak

(c) Black Sea basin—synoptic chart, February 5, 2020, 12.00 UTC:

(d) February 5, 2020, Hellenic Center for Marine Research, atmospheric pressure, surface wind, surface temperature, accumulated rainfall; public pictures from [14]:

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6.2 Short History of the Black Sea’s Storms

195

(e) Weather: nline wind charts [15]:

(f) February 5, 2020, Meteo Romania meteo data: relative humidity, total nebulosity, air temperature, wind speed, precipitation; public pictures from [16]:

(g) Constanţa—main meteorological parameters, February 5–6, 2020: (public graphs from [16])

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– Relative humidity

– Nebulosity

6.2 Short History of the Black Sea’s Storms

– Air temperature

– Wind speed

197

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– Air temperature

– Precipitations

Sulina—main meteorological parameters, February 5–6, 2020: (public graphs from [16])

6.2 Short History of the Black Sea’s Storms

– Relative humidity

– Nebulosity

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– Air temperature

– Wind speed

6.2 Short History of the Black Sea’s Storms

– Air temperature

– Precipitation

201

202

6.3

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

Naval Accidents in the Black Sea

The study of the international, Romanian and Turkish public data allowed us an incomplete analysis of the catastrophes, accidents, and naval incidents in the Black Sea starting with 1960 and until now (Table 6.2). A statistical analysis of the circumstances in which these unfortunate events occurred in the Black Sea looks like this (Tables 6.2. and 6.3 and Figs. 6.16 and 6.17): Tabel 6.3 Black Sea—number of naval accident per month Month January February March April May June

Number of accidents 4 3 3 4 2 -

6.3 Naval Accidents in the Black Sea

203

Table 6.2 Naval accidents in the Black Sea, 1960–2021 Date December 14, 1960

Ship Petar Zoranic, World Harmony

Place Bosporus

September 15, 1964

Norborn

Bosporus

March 1, 1966

Lutsk, Cransky Oktiabr

Bosporus

July 3, 1966

Yeni Galatasaray

Bosporus

November 18, 1966 October 15, 1968 July 1, 1970

Bereket, Ploieşti Evangelia

Bosporus

Ancona

Bosporus

December 27, 1972

Turan Emeksiz, Sönmezler Fucsia

Bosporus

February 4, 1977

Romanian coast

Port of Constanţa

April 21, 1979

Carpaţi, Kefeli

Bosporus

November 15, 1979

Independenţa, Evriali

Bosporus

April 2, 1980 November 9, 1980

Elsa, Moskovosky Nordic Faith, Stravanda

Bosporus

February 19, 1981

Akra Action

Bosporus

Romanian coast

Accident Yugoslavian flagged M/T Petar Zoranic, carrying gasoline, collided with the Greek tanker M/T World Harmony at Kanlıca Point, 18,000 tons of oil spilled and caused pollution. The fire lasted for some weeks and suspended transit traffic. The Turkish vessel Tarsus collided with the Petar Zoranic and burnt with it. 20 dead. Norwegian flagged vessel Norborn contacted the wreck of M/T Petar Zoranic at Kanlica Point. A fire broke out and oil spilled. Soviet flagged vessels M/T Lutsk and M/T Cransky Oktiabr collided at Maiden’s Tower Point. 1850 tons of oil spilled, caught fire, and caused the Turkish passenger ferryboat Kadıköy and the ferry boat terminal of Karaköy burn completely. Turkish passenger ferryboat Yeni Galatasaray collided with lumber carrying Turkish coaster Aksaray. 13 dead. Turkish passenger ferryboat Bereket hit the Romanian flagged M/V Ploiesti. 8 dead. Greek flagged M/V Evangelia grounded near Costinesti. Italian M/V Ancona ran ashore and caused the downfall of a building under construction. 5 dead. Turkish vessels, the passenger ferryboat Turan Emeksiz and the M/V Sönmezler collided. 5 dead. Greek M/V Fucsia grounded in Constanţa port pier 60, moved in a construction area on October 28, 1977. Romanian flagged vessel M/V Carpaţi collided with the Turkish ship M/V Kefeli. 11 dead. Romanian flagged M/T Independenţa collided with Greek M/V Evriali at Haydarpaşa Point. 94,600 tons of crude oil spilled and the following fire lasted weeks. 43 dead. Greek ship M/V Elsa collided with the Soviet vessel M/V Moskovosky. 2 dead. British M/VNordic Faith collided with Greek flagged M/S Stravanda. Fire broke out. Greek flagged M/V Akra Action had grounded near Vama Veche and after sunk. (continued)

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Table 6.2 (continued) Date October 13, 1982 September 24, 1985 October 29, 1988

Ship Unirea

Place Bulgarian waters

TCG Meltem, A Soviet Navy ship Blue Star, Gaziantep

Bosporus

Bosporus

December 2, 1988

Sadu

Northern breakwaters Port of Constanţa Near Port of Galaţi, Romania

September 10, 1989

Mogoşoaia

March 25, 1990

Jampur, Da Tung Shang

Bosporus

November 14, 1991

Madonna Lily, Rabunion XVIII

Bosporus

March 13, 1994

Nassia, Shipbroker

Bosporus

January 4, 1995

Paris, You Xiu

December 29, 1999

Volganeft-248

Northern breakwaters Port of Constanţa Bosporus

October 7, 2002

Gotia

Bosporus

Accident Romanian flagged T/V Unirea sunk 40 miles offshore Cape Kaliakra. 1 dead. Turkish Navy fast attack boat TCG Meltem collided with a Soviet Navy warship. Meltem sunk. 5 dead. Maltese flagged ammoniac carrier M/T Blue Star contacted the Turkish crude oil tanker M/T Gaziantep, which was on anchor at Ahırkapı Point. 1000 tons of ammoniac spilled in the Marmara Sea. Romanian flagged M/V Sadu sunk near the northern breakwaters, port of Constanţa. 15 dead. Romanian flagged inland passenger ship Mogosoaia collided by Bulgarian inland tug Petar Karamincev sunk at Cotu Pisicii, near port of Galaţi. 270 dead. Iraqi flagged M/T Jampur carrying gasoline collided with the Chinese flagged bulk carrier M/V Da Tung Shang at Sarıyer Point. 2600 tons of oil spilled from Jampur and caused severe pollution. Philippines flagged M/V Madonna Lily collided with the Lebanese flagged livestock carrier M/V Rabunion XVIII at Anadoluhisarı Point. 21,000 sheep drowned sunk and their corpses caused major pollution. 5 dead. Cyprus flagged M/T Nassia collided with the bulk carrier M/V Shipbroker. 9000 tons of petroleum spilled and 20,000 tons burnt four days long affecting the marine environment severely. Traffic in the Strait was suspended for several days and Shipbroker burnt totally. 27 dead. Malta-flagged M/V Paris and Hong Kongflagged You Xiu sunk after collided the breakwaters. 54 dead. Russian Federation flagged M/T Volganeft248 grounded at Florya Point with 4000 tons of fuel oil on board and split into two pieces. 1578 tons of oil spilled to the sea. Clean-up operation of the contaminated recreational beaches took about two years. Malta-flagged M/V Gotia stranded at Bebek Point. 22 tons oil spilled causing environmental damage to the boats in the marina and the structures at the waterfront. (continued)

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205

Table 6.2 (continued) Date November 10, 2003

Ship Svyatoy Panteleymon

Place Bosporus

July 26, 2007 November 10–11, 2007

Multi Trader

Romanian coast

Vologoneft139, Volnogorsk, Nahichevan, Kovel

Kerch Strait

November 10, 2007 September 1, 2010 May 4, 2013

Yldirimlar 1

Romanian coast

Medy

Romanian coast

Erdem Karadeniz, Kalamis Erhan Araz

Bosporus

Bosporus

Captain Omar

Bosporus

October 1, 2013

Anafarta

Bosporus entrance

October 22, 2013

Volgo-Balt 193

Bosporus

October 28, 2013

YM Miranda

Bosporus

November 13, 2013

Tala

Bosporus

September 6, 2013 September 14, 2013

Accident Georgian flagged M/V Svyatoy Panteleymon ran aground off Anadolu Feneri and broke into two pieces. Around 500 tons of oil spilled and caused pollution. Cambodgian M/V Multi Trader sunk near Venus Resort. Volgoneft-139 broke into-two and bow sank in the vicinity of the main ship channel of the Strait at the 10 m depth. Volnogorsk, Nakhichevan, and Kovel did not sink immediately but drifted towards the coast of Ukraine to the South from the Tuzla Island. The accident became considered an ecological catastrophe, one of the worst in the region and the gravest since the early 1990s. 5 dead, 17 missing people. Romanian flagged fishing boat Yldirimlar. 1 sunk near Port of Midia, 1 dead. Turkish flagged M/V Medy sunk about 4 miles offshore. The ferries Erdem Karadeniz and Kalamis collided in heavy early-morning fog. 4 injured. Turkish M/V Erhan Araz ran aground near Beykoz. Togo flagged M/v Captain Omar experienced an engine failure during transit of the straits. She was towed to Beykoz. Turkish m/v Anafarta took on water at the Black Sea entrance to the strait. She was intentionally grounded to prevent her from sinking. The crew were safely taken off. Cambodian flagged m/V Volgo-Balt 193 suffered a mechanical problem in transit near Maiden’s Tower that required her to be towed to a safe harbor. Maltese flagged chemical tanker YM Miranda suffered an engine fire in the straits. In distress, the master deployed one or more anchors. These destroyed one fiber-optic undersea cable and damaged another near Anadolu Hisari. The straits were closed as tugboats rendered assistance. Liquid propane gas tanker Tala suffered an engine failure requiring the assistance of a tug. (continued)

206

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

Table 6.2 (continued) Date October 8, 2014

Ship Fortuna S

Place Romanian waters

August 17, 2016

TCSG-25, Tolunay

Bosporus

April 27, 2017

Liman, Youzarsif H

Turkish waters

April 7, 2018

Vitaspirit

Bosporus

January 7, 2019 January 21, 2019

Volgo Balt 214 Maestro, Kandy

Turkish coast

February 16, 2019

Fehn Lyra

Turkish coast

January 17, 2021 March 11, 2021

Arvin

May 16, 2021

Shark 1

Turkish waters 70 nautical miles west Constanţa port 7 nautical miles west Midia port

Volgo Balt 179

Kerch Strait

July August September October November December Total

Accident Fortuna S general cargo ship, en route from Giurgiuleşti and carrying 2650 tonnes of salt to Syria, ran aground and sank in the Sulina seaway, Romania. The ship collided with the south pier and suffered extensive water ingress. No injuries. Turkish Coast Guard vessel TCSG-25 collided with the Cook Island flag and Turkish owned bulk carrier M/V Tolunay, near the southern entrance of Bosphorus. 4 dead. Russian Federation Surveillance Liman has sunk after a collision with Togo - flagged freighter Youzarsif H. No casualties. Maltese-flagged Panamax Vitaspirit crashed into the eighteenth century Hekimbasi Salih Efendi Mansion after its steering gear failed. M/V Volgo Balt 214 sank in rough seas off the Turkish coast. 6 dead. Tanzanian-flagged Turkish ships’ Maestro and Kandy, caught fire while transferring liquefied gas from one vessel to another in the Kerch Strait. 20 dead. Latvia flagged Fehn Lyra has pushed ashore in bad weather 2 nautical miles off Kefken, Kandıra coast east of the Bosphorus Palau flagged M/V Arvin sunk in a rough sea. 4 dead. Commore flaged MV Volgo Balt 179 sunk in rough sea. 2 dead and 1 missing. Romanian flag sunk. 3 dead and 2 missing.

3 1 6 6 8 4 42

In the Black Sea in the period 1960–2020 (60 years), there were 42 naval accidents in which 62 ships were involved and lost and 526 people (sailors and passengers) lost their lives. The causes of these events are multiple, the main ones

6.3 Naval Accidents in the Black Sea

207

Table 6.3 Black Sea accidents, lost ships, human casualties, probable causes, 1960–2021 Year 1960 1964 1966 1968 1970 1972 1977 1979 1980 1981

Number of accidents 1 1 2 1 1 1 1 2 2 1

Number of lost ships 2 1 3 1 1 1 1 4 4 1

Human casualties 20 – 8 – 5 5 – 54 – –

1982 1985 1988

1 1 2

1 2 3

1 5 15

1989 1990 1991 1994 1995 1999 2002 2003 2007 2010 2013 2014 2016 2018 2019 2021 Total

1 1 1 1 1 1 1 1 3 1 6 1 1 1 3 1 42

2 2 2 2 2 2 2 2 5 1 8 1 1 1 3 1 62

270 – 5 27 54 – – – 23 – – – 4 – 26 4 526

Probable causes of accidents Human error Human error Human error Human error, bad weather Human error Human error Human error Human error, bad weather Human error Human error, bad weather, technical Probably a WW II mine Human error Human error, bad weather, technical Human error, bad weather Human error Human error Human error, technical Human error, bad weather Human error, technical Human error, technical Human error, technical Human error Human error Human error, bad weather Human error Human error Human error Human error, technical Human error, bad weather

being: human error, bad weather, and technical ones. The material and financial damages were huge, to which were added the pollution of the marine environment with hydrocarbons and other pollutants (as it was negative in some cases, for years), with tragic consequences for the marine environment.

208

6

The Influence of Weather and Climate Factors on the Navigation and Seaborne. . .

8 7 6 5 4 3 2 1

No. accidents

Fig. 6.16 Black Sea—accidents and lost ships, 1960–2021 8 7 6 5 4 3 2 1 0

No. of accidents

Fig. 6.17 Black Sea—number of naval accidents per month

2021

2018

2019

2016

2014

2013

2007

2010

2003

1999

No. of lost ships

2002

1994

1995

1991

1990

1989

1985

1988

1981

1982

1979

1980

1972

1977

1970

1966

1968

1964

1960

0

References

209

References 1. ***Romanian Black Sea Pilot Volumes 1 and 2 with amendments, EX PONTO Publishing House, Constanta, (in Romanian), 2006. 2. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 3rd Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2010. 3. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 4th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2013. 4. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 5th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2017 5. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24 6th Edition, UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2019 6. Boşneagu R (2004) Geographical conditions influence of the maritime routes in the Black Sea basin (Western sector). Publishing House Bucharest, Romania, (in Romanian), Cartea Românească 7. ***https://www.loc.gov/pictures/item/2004672563/. Accessed 19.01.2021 8. ***http://www.blacksea-commission.org/_publ-KerchReport.asp, Accessed 19.01. 2021 9. ***https://arxiv.org/ftp/arxiv/papers/1304/1304.6535.pdf. Accessed 19.01.2021 10. Masters J., https://www.wunderground.com/blog/JeffMasters/black-sea-storm-causes-ecologi cal-disaster-powerful-bay-of-bengal-cyc.html, Accessed 19.01.2021 11. Pydynowski K., https://www.accuweather.com/en/weather-news/ship-with-12-crew-memberscapsizes-amid-storm-in-black-sea/361058. Accessed 19.01.2021 12. Korosek M, Violent windstorm with locally hurricane-force wind gusts in excess of 200 km/h (¼125 mph) is expected across the eastern Adriatic (Croatia) tonight, https://www.severeweather.eu/mcd/violent-windstorm-adriatic-croatia-mk/. Accessed 5.02.2020 13. ***https://mgm.gov.tr/eng/marine-daily-report.aspx. Accessed 5.02.2020 14. ***http://poseidon.hcmr.gr/weather_forecast.php?area_id¼bsea. Accessed 5.02.2020 15. ***Wheather Online, https://www.weatheronline.co.uk/marine/weather?LEVEL¼3& LANG¼en&MENU¼0&TIME¼21&MN¼gfs&MODELLTYP¼uv10&MEER¼schw 16. ***http://www.meteoromania.ro/avertizari-nowcasting/. Accessed 5 and 6.02.2020

Chapter 7

The Specific Hydrological Factors of the Black Sea Basin

Abstract In the Black Sea basin, the water exchange toward and from the Black Sea is comparatively insignificant to the total volume of the water from its basin. The Black Sea water level is subject to periodical and nonperiodical vertical oscillations. The volume fluctuations are produced due to the changes occurring in the hydrological balance. The Black Sea basin and the sea itself form a single unified natural system. The rivers form a link between the landmass and the sea, supplying the marine reservoir with water discharge and output from erosion and denudation. Keywords Black Sea · Hydrological factors

7.1

The Water Balance and the Water Exchange Through the Straits

In the scientific literature, the former calculated values of the Black Sea hydrological balance are within fairly wide limits [1] (Table 7.1). In Sukhovey’s opinion (1986), the Black Sea hydrological balance is as follows [2]: – – – –

Evaporations: 360 km3/year Precipitations input: 230 km3/year River runoff: 310 km3/year Water exchange with the Azov Sea: 33.8 km3/year towards the sea and 49.2 km3/ year from the sea – Water exchange with the Marmara Sea: 398 km3/year towards and 193 km3/year from it In Resetnikov’s opinion (1992) [2], the hydrological balance of the Black Sea is as follows:

– – – –

Evaporations: 370 km3/year Precipitations input: 225 km3/year River runoff: 353 km3/year Water exchange with the Azov Sea: 0 km3/year towards and 22 km3/year from it

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_7

211

212

7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.1 The Black Sea hydrological balance

Water input River runoff Precipitations Water exchange with the Marmara Sea Water exchange with the Azov Sea Total uptake Error Balance

Values Km3 320–346 145–230

Water losses mm 690–841 289–310

176–202

427–467

53–95 667–827 10 704

Values Km3 319–332 340–392

mm 690–883 750–949

32–70

78–169

129–230

Evaporations Water exchange with the Marmara Sea Water exchange with the Azov Sea –

–

–

1440–2001 24 1712

Total losses Error Balance

667–827 0 704

1440–2001 0 1712

– Water exchange with the Marmara Sea: 227 km3/year towards and 0 km3/year from it – Total freshwater: 208 km3/year – Total input: 230 km3/year – Total output: 227 km3/year After Jaoshvili et al. (2002) the Black Sea Basin rivers can be divided into three categories [3]: 1. Large rivers which rise high in the mountains, with a catchment area of more than 1500 km2 and an average annual flow of more than 100 m3/s (Bzyb, Kodori, Rioni, and Chorokhi). The Inguri also belonged in this category before it was artificially controlled. 2. Rivers of average size with their sources in the spurs of the Caucasian and Meskheti ridges, with a water catchment area of 100–1500 km2 and an average annual flow of 5–50 m3/s (Pshchada, Vulan, Shapsukho, Tuapse, Ashe, Psezuapse, Shakhe, Sochi, Mzymta, Psou, Khashupse, Khipsta, Aapsta, Gumista, Kelasuri, Madjarka, Mokva, Galidzga, Okumi, Khobi, Supsa, Natanebi, Kintrishi, and Chakvistskali). 3. Small rivers with a catchment area of 50–100 km2 and an average annual flow of less than 5 m3/s (Mezyb, Dzhubga, Tu, Nebug, Agoi, Dagomys, Matsesta, Khosta, Kudepsta, Zhove-Kvara, Besleti, Tumush, Korolistskali, etc.). Rivers with an average annual discharge of 348 km3 of freshwater drain into the Black Sea. 86% of this outflow comes from ten major rivers (Table 7.2 and Figs. 7.1 and 7.2) [3]: Due to the physical and geographical specific conditions of the Black Sea, the water exchange towards and from the Black Sea is comparatively insignificant to the total volume of the water from its basin [3]. The Black Sea water level is subject to periodical and nonperiodical vertical oscillations. The volume fluctuations are produced due to the changes occurring in the hydrological balance (e.g., the seasonal fluctuations are at a maximum during the winter season and at a minimum in the cold season) [3]. The Black Sea basin and the sea itself form a single unified natural

7.1 The Water Balance and the Water Exchange Through the Straits

213

Table 7.2 Main rivers’ annual discharge—Black Sea River Danube Dnieper Rioni Dniester Çoruh Kizil Irmak Sakarya Yesil Irmak Kodori Bzyb

Annual average discharge 200 km3 43.5 km3 13.37 km3 9.1 km3 8.71 km3 5.90 km3 5.60 km3 5.30 km3 4.17 km3 3.79 km3

Fig. 7.1 Black Sea – main rivers’ annual discharge

Percentage—total discharge 57.5% 12.5% 3.8% 2.6% 2.5% 1.7% 1.6% 1.5% 1.2% 1.1%

13,4 43,5

9,1

8,7

Danube

5,9 5,6 5,3

Dnieper

4,2

Dniester

3,8

Rioni

Çoruh Kizik Irmak Sakarya

200,0

Yesil Irmak Kodori Bzyb

system. The rivers form a link between the landmass and the sea, supplying the marine reservoir with water discharge and output from erosion and denudation. As a result, the River-Estuary-Sea chain can be regarded as a unified natural system [3]. The breakdown of discharge, by state and region, is presented below (Table 7.3 and Figs. 7.3 and 7.4). Under natural conditions, the discharge would have been more than 381 km3. In addition to the surface discharge, at least 17 km3 of freshwater reaches the Black Sea from underground sources. Precipitation contributes another 238 km3 (562 mm precipitation). Thus the annual volume of freshwater entering the Black Sea (river water plus precipitation plus underground sources) is on average 603 km3. Under natural conditions, without human interference, this figure would be 636 km3 [3]. The inflow of river water and load into the Black Sea is very diverse and depends on the natural conditions on the adjacent landmass and of the sea itself. The entire process is also subject to prevailing geographical zonal conditions (Table 7.4 and Fig. 7.5). After Romanou et al. (2010), the hydrological balance of the Black Sea components (km3/year) are as follows [4]:

214

7 The Specific Hydrological Factors of the Black Sea Basin

Black Sea KHERSON ODESA

CHORNOMORS’KE

Danube

KERCH SULINA

NOVOROSIYSK YALTA CONSTANŢA

VARNA

BURGAS

River Danube Dnieper Rioni Dniester Çoruh Kizil Irmak Sakarya Yesil Irmak Kodori Bzyb

ISTANBUL AIRPORT

Annual average discharge 200 km 3 43.5 km 3 13.37 km 3 9.1 km 3 8.71 km 3 5.90 km 3 5.60 km 3 5.30 km 3 4.17 km 3 3.79 km 3

Percentage - total discharge 57.5% 12.5% 3.8% 2.6% 2.5% 1.7% 1.6% 1.5% 1.2% 1.1%

TUAPSE

ADLER

BATUMI

ZONGULDAK SAMSUN TRABZON

Fig. 7.2 Black Sea – main rivers’ annual and percentage discharge Table 7.3 The breakdown of discharge by state and region State/region Danube Bulgaria Turkey Georgia Russian Federation Ukraine Crimea Other

The volume of water entering the sea 200 km3 1.8 km3 38.0 km3 46.0 km3 6.5 km3 55.5 km3 0.3 km3

Fig. 7.3 Black Sea – breakdown of discharge by state and region

1,9

57.3% 0.52% 10.9% 13.2% 1.9% 15.9% 0.08% 0.2%

Danube Bulgaria

13,2 15,9

0,08

10,9 0,52

0,2

Turkey Georgia Russian Federaon Ukraine

57,3

Crimea Other

7.1 The Water Balance and the Water Exchange Through the Straits

215

Black Sea Ukraine KHERSON ODESA

CHORNOMORS’KE

55.5 km3/15.9% SULINA

200 km3/57.3%

Russian Federation

KERCH

Crimea NOVOROSIYSK

Romania

YALTA

CONSTANŢA

6.5 km3/1.9%

TUAPSE

3

0.3 km /0.08%

ADLER

Bulgaria VARNA

Georgia 3

BURGAS

1.8 km /0.52% 38.0 km3/10.9% 46.0 km3/13.2%

ISTANBUL AIRPORT

BATUMI

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.4 The breakdown of discharge by state and region Table 7.4 River load distribution by region, in million m3

Region North-eastern part Eastern part Southern part Western part Danube North-western part Crimea Total

Current river load volume Total 0.93

River load volume before flow control Shoreline 0.32

Marine 0.61

1.00

11.1 8.00 0.45 30.0 1.66

4.30 2.50 0.10 3.00 1.50

6.80 5.50 0.35 27.0 0.16

14.5 25.5 0.85 50.0 3.00

0.075 52.2

0.25 11.7

0.050 40.5

0.09 94.0

– Evaporations: 341 km3/year – Precipitations input: 204 km3/year Considering that the Black Sea volume is 529,955 km3, the hydrological balance is as follows [4]: – The river runoff (i.e., the average of 330 km3) is about 0.6‰ of the total volume of the sea; most of this contribution is from the Danube and Dnieper rivers (representing 81%), out of which 64% belongs to the Danube.

216

7 The Specific Hydrological Factors of the Black Sea Basin

Black Sea Ukraine KHERSON ODESA

SULINA

Romania

Total Shoreline Marine 1.66 1.50 0.15 Total Shoreline Marine 30.00 3.00 27.00

CONSTANŢA

CHORNOMORS’KE

NOVOROSIYSK YALTA

Total Shoreline Marine 0.32 0.61

Total Shoreline Marine0.93 0.095 0.25 0.050 Bulgaria VARNA

BURGAS

Total Shoreline Marine 0.45 0.10 0.35

ISTANBUL AIRPORT

Russian Federation

KERCH

Crimea

TUAPSE

ADLER

Black Sea Total Shoreline Marine 52.2 11.7 40.5

Georgia Total Shoreline Marine 11.1 4.30 6.80

Total Shoreline Marine 8.00 2.50 5.50

BATUMI

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.5 River load distribution by region, in million m3

– The water exchange with the Azov Sea through the Kerch Strait is about 0.35‰ from the total volume. – The water exchange with the Marmara Sea through the Bosphorus Strait is about 0.21‰ from the total volume of the sea. – The total water intake and losses are equal or almost equal, i.e., 667–694 km3 towards 667–704 km3, and they represent 1.28‰ from the total sea volume. – The water losses through the Bosphorus Strait are higher (i.e., 340 km3) than the water intake (176 km3). – The water intake through the Kerch Strait (53 km3) is higher than the water losses (32 km3). – The water intake from rivers and precipitations (465 km3) is compensated by the losses through the straits and evaporations (704 km3). After Efimov et al. (2012), the hydrological balance of the Black Sea calculated components (km3/year) are as follows [5]: – – – – –

Computed amount of precipitation, 235 km3/year (564 mm). Evaporation, 385 km3/year (924 mm). River runoff, 350 km3/year (840 mm). Water balance in the Kerch Strait 20 km3/year (48 mm). The balance of water discharge in the Bosphorus can be estimated as 220 km3/ year (528 mm); this value almost corresponds to the mean value of 217 km3/year (521 mm) from different literature sources.

Recent studies (Zavialov et al. 2020) show that a large salinity difference between the Azov and Black seas results in substantially different spreading and mixing

7.2 The Black Sea Thermohaline and Density Regimes

217

dynamics of waters that flow from the Sea of Azov into the Black Sea. Different physical mechanisms govern water transport in southward (from the Sea of Azov to the Black Sea) and northward (from the Black Sea to the Sea of Azov) directions. Analysis of satellite imagery, wind data, and numerical model outputs shows that water exchange in the Kerch Strait is governed by the wind-induced barotropic pressure gradient. As a result, water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time [6].

7.2

The Black Sea Thermohaline and Density Regimes

In the scientific literature, it is shown that the Black Sea area gains annually 93,000 calories per square centimeter. The average values of the heat balance elements (Table 7.5 and Figures 7.6a, b) are distributed as follows: 88% heat input by direct Table 7.5 The Black Sea thermic balance Components Possible global radiation Real global radiation Albedo Absolute global radiation Effective radiation Radiative balance Turbulent river Heat quantity, consumed by evaporation Thermic balance Error

47,6

25,8

21,8

51,6 99,2

180,3

Coastline Kcal/cm2 year 180.3 132.3 25% 99.2 51.6 47.6 25,8 21.8 47.6 47.6–47.6 ¼ 0

56,7

7,8

Sea Kcal/cm2 year 180.3 117.0 9% 106.1 49.4 56,7 7.8 46.4 54.2 54.2–56.7 ¼ 2.5

46,4

49,4 132,3

Possible global radiaon Real global radiaon Absolute global radiaon

106,1

117

Possible global radiaon Real global radiaon Absolute global radiaon Effecve radiaon Radiave balance Turbulent river

Fig. 7.6 The Black Sea thermic balance (a) coastline, (b) sea

180,3

218

7 The Specific Hydrological Factors of the Black Sea Basin

solar radiation, and 12% by positive convective turbulent heat exchange, respectively, losses by evaporation 76%, and 24% by inverse convective turbulent heat exchange and effective radiation [1]. The vertical distribution of the Black Sea waters’ temperature has the following characteristics: – Into the upper layer, up to a depth of 150 m (representing 12% of the total volume of the seawater), the water temperature varies between 1.4 and + 26  C. – From a depth of 200 m (representing 88% of the total water volume), the temperature remains practically constant at the value of 8–9  C, with a lower temperature to the bottom. The significant thermic variations occur only in the surface layers of the Black Sea, i.e., due to the limit of the waves influence and marine currents, while in most of the water volume, there is obvious thermic inertia. In the coastal areas, the convective miscellany occurs up to the depth of 60–80 m; during the summer season, this layer is thinner and the temperature’s drop occurs at the depth of 20 m; during the winter, the surface temperature drops to 6–7  C, to 8–9  C in the southwest and 2–3  C and even - 0.6  C in the northern part. During the summer season, the surface temperature rises to 24–25  C in the east and in the south (20–22  C represent usual temperatures there), and in Karkinit Bay, the highest temperature recorded was 26.9  C (1989). At the sea surface, the average temperature’s distribution generally follows the annual average air temperature’s distribution over the Black Sea basin. The annual average of the water temperature’s horizontal distribution varies between 11 in the north of the Sea (the Gulf of Odesa) and 16 in the east (Batumi), having extreme values during the warm period (24 ) and in the cold period (1 ). During winter, the average surface temperature ranges from 6–7  C in the western basin to 7.4–8.4  C in the eastern Black Sea basin (Fig. 7.7) [7]. The average temperature of the coastal waters during the warm season is between 19  C in the north-west Black Sea part and 24  C in the extreme SE part of the sea (Fig. 7.8) [7]. In the western Black Sea basin, substantial changes of the temperature of the coastal and surface waters masses occur, sometimes in the adjacent transition area up to 150–200 m, too. During wintertime, the upper layer (i.e., between 60 and 80 m) cools up to 6 –7  C, and in the northern and north-western boundary of the basin even to 0.5–3  C. During springtime, under the influence of the radiative processes and the miscellany of currents and waves, the surface waters begin to warm gradually, sometimes reaching values of 24–25  C (e.g., in July–August). The heating of the upper layer temperature is slow, reaching the stable temperature of 9  C (in April–May), thus completely restoring the winter losses [8]. In the early autumn, the further warming of the upper water layer produces sometimes the interlayer’s disappearance (i.e., in the conditions of a warm summer and a not– too-cold previous winter). At the beginning of the autumn, the water temperature decreases uniformly, from 22–23  C at the surface to 9–9.1  C at the sea bottom; thus, at a depth of over 2000 m, the surface layer becomes homeothermic around the values between 6.5 and 7.5  C. Up to 200 m depth, the water temperature slightly

7.2 The Black Sea Thermohaline and Density Regimes

219

Black Sea Ukraine KHERSON ODESSA

Russian Federation CHORNOMORS’KE SULINA

7.2

Crimea

7

KERCH NOVOROSIYSK

Romania

YALTA

7.4 7.4 4

8

CONSTANŢA

7

TUAPSE

8

Bulgaria

ADLER

VARNA

7

Georgia

7.4

7

7.8

BURGAS

7.4 POTI

8.4 8 8

BATUMI

ISTANBUL AIRPORT

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.7 The average temperature at the water surface in the Black Sea basin, February. (Processed after Shuisky, 1993)

Black Sea Ukraine KHERSON ODESSA

19 20

19 21

Crimea

21

Romania

Russian Federation

CHORNOMORS’KE

SULINA

20

YALTA

KERCH

23

20

NOVOROSIYSK

21

CONSTANŢA

TUAPSE

21

ADLER

21

Bulgaria

24

VARNA

Georgia

23 22 BURGAS

23

23

22 ISTANBUL AIRPORT

24

22 23

BATUMI

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.8 The average water temperature at the surface in the Black Sea area in July. (Processed after Shuisky, 1993)

220

7 The Specific Hydrological Factors of the Black Sea Basin

Fig. 7.9 Water temperature in the western Black Sea basin—the annual average

12 12.5 13

13.5

14

14.5

15

15.5 ISTANBUL

increases to 8.6–8.8  C; at over 1000 m depth, the recorded temperature is 9  C, increasing then to the sea bottom at 9.1  C, after then, the phenomenon repeats once its spring. It can be concluded that into the upper layer (i.e., up to 80 m depth), the water temperature is subject to some seasonal fluctuations; every season is characterized by an absolute typical temperature value and stratification as well, while the deep water’s temperature remains relatively constant. The annual average temperature of the surface water varies from 12  C (in NW) to 15  C in the southern basin, while the annual amplitude average is inversely oriented, from 17  C in the south to 20  C in the north-western part, for 2000–2010 period (Figs. 7.9 and 7.10) [9]. Research on the Sea Surface Temperature (SST) in the Black Sea (Miladinova et al. 2017) concludes that: regarding the spatial distribution of SST in the Black Sea, the most noticeable characteristic is its increase in the direction from northwest to southeast for all seasons. It is worth noting the decreased SST in the center of the eastern gyre, alongside the Rim Current in the western part of the basin and central part of the Anatolian coast. Here it is notable that the bias in the western and central basin is largely negative, except for the south-western shelf, while it is positive in the

7.2 The Black Sea Thermohaline and Density Regimes

221

Fig. 7.10 Water temperature in the western Black Sea basin—the annual amplitude

21 20 19 18 17

23

23 21 24

16

17

15

16 17

ISTANBUL

Fig. 7.11 (a) Calculated climatological mean SST for 1982–2009. (b) Bias of model climatology compared to Pathfinder climatology (Pathfinder data, http://www.nodc.noaa.gov/sog/pathfinder4 km/). (By courtesy of Prof. G. Miladinova [10])

eastern basin. Differences along northern continental boundaries and the Anatolian coast are relatively larger (from 0.7 to 1.0  C) (Fig. 7.11a, b) [10]. Sakalli and Başusta (2018) in their article Sea surface temperature change in the Black Sea under climate change: a simulation of the sea surface temperature up to 2100, conclude that: the surface temperature of the Black Sea increased due to climate change during the 20th century and continues to rise. The largest monthly

222

7 The Specific Hydrological Factors of the Black Sea Basin

Black Sea

Ukraine KHERSON ODESSA

Russian Federation

13 13.5 SULINA

CHORNOMORS’KE

14 KERCH

Romania

NOVOROSIYSK

14.5

YALTA

4

CONSTANŢA

TUAPSE

14.5

ADLER

Bulgaria 15

VARNA

BURGAS

Georgia

15 15.5 16

ISTANBUL AIRPORT

ZONGULDAK

Turkey

16.5 BATUMI

SAMSUN TRABZON

Fig. 7.12 Black Sea–Sea surface temperature, 1982–2015. (Modified after Sakalli and Başusta [11])

fluctuations in SST were during late summer (August) and autumn (November). At the end of this century, the relative increase in average Black Sea SST is predicted to be 5.1  C [11]. Also, they present the mean time of the Black Sea SST for the 1982–2015 period (Figure 7.12). The SST monthly average on the Black Sea coast, calculated based on data for the last five periods (2015/2016–2019/2020), [12] show minimum values in February 3.32  C in Odesa, and 3.96  C in Zatoka, in the northwestern part, and maximum values in August of 27.22  C at Tuapse, and 27.18  C at Gagra, in the eastern part (Table 7.6 and Fig. 7.13). The SST multiannual average values on the Black Sea coast (for 14 points), calculated based on data for the last five periods (2015/2016–2019/2020) [12], show minimum values in 2017 (15.22  C) and maximum in 2018 (16.44  C), with a minimum value of 12.5  C in Odesa (the average SST value in Odesa in 2017 was 11,82  C) and a maximum of 17,78  C in Batumi (the SST average value in Batumi in 2018 was 18,76  C) (Table 7.7 and Figs. 7.14 and 7.15). The SST multiannual average values on the Black Sea coast (for 14 points), calculated based on data for the last five periods (2015/2016–2019/2020) for the four seasons [12] are presented in Tables 7.8, 7.9, 7.10, and 7.11 and in Figs. 7.16, 7.17, 7.18, and 7.19, with an average of 7.36  C in February, 16.34  C in May, 25.72  C in August, and 14.48  C in November.

Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Eupatoria Odesa Zatoka Black Sea Coast

Jan 6,08 6,82 7,04 9,16 10,86 10,68 10,66 10,64 6,64 9,72 9,26 8,12 4,32 4,44 8,17

Febr 5,46 6,26 6,36 8,02 9,48 9,58 9,62 9,62 6,18 8,92 8,62 7,58 3,32 3,96 7,36

Mar 6,9 7,26 6,16 8,64 9,66 9,92 9,92 9,74 7,28 9,04 8,76 8,2 4,92 5,4 7,99

Apr 10,14 10,32 10,58 10,84 12 12,34 12,26 12,22 11 10,82 10,54 10,48 9,3 9,54 10,88

May 15,78 16,18 16,42 15,88 17,1 17,38 17,38 17,22 16,96 15,92 15,44 15,86 15,56 15,64 16,34

Table 7.6 SST monthly average (2016–2019), processed after [11] Jun 21,38 21,6 21,8 21,34 22,84 22,68 22,84 22,8 22,08 21,46 21,14 21,06 21,24 21,38 21,83

Jul 24,4 24,64 25,06 24,98 25,8 25,8 25,8 25,7 25,1 24,52 24,02 23,74 23,58 24,06 24,80

Aug 25,28 25,58 25,72 25,58 26,92 27,18 27,22 27,16 25,36 25,06 25,04 24,94 24,3 24,78 25,72

Sep 22,78 23,36 23,54 24,06 25,16 25,24 25,1 25,02 22,62 23,04 22,9 22,7 21,52 21,86 23,49

Oct 17,72 18,56 18,88 19,9 22,22 21,02 20,74 20,62 16,82 18,22 18,26 17,94 16,04 16,38 18,81

Nov 13,38 14,4 14,64 16,02 17,12 16,8 16,6 16,38 11,98 14,32 14,14 13,54 11,5 11,9 14,48

Dec 9,82 10,3 10,68 12,14 13,32 13,12 13,06 12,9 9 11,45 11 10,34 7,4 7,74 10,88

Average 14,93 15,44 15,57 16,38 17,71 17,65 17,60 17,50 15,09 16,04 15,76 15,38 13,58 13,92 15,86

7.2 The Black Sea Thermohaline and Density Regimes 223

224

7 The Specific Hydrological Factors of the Black Sea Basin

27 24 21 18 15 12 9 6 3

Jan

Febr

May

Apr

Mar

Jun

Fig. 7.13 Black Sea coast—SST monthly average (2016–2019) Table 7.7 Black Sea—SST multiannual average 2015/2016–2019/2020 Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Eupatoria Odesa Zatoka Black Sea coast SST multiannual average

2016 14,93 15,42 15,12 16,63 17,53 17,41 17,26 17,18 15,04 16,01 15,74 15,39 12,33 13,62 15,69

2017 14,24 14,63 14,94 15,72 16,99 17,03 16,95 16,83 14,72 15,53 15,32 14,96 11,82 13,33 15,22

2018 15,62 15,76 16,06 16,66 18,76 18,58 18,39 18,18 15,53 16,70 16,33 15,88 13,15 14,52 16,44

2019 15,50 16,11 16,23 16,63 17,85 17,74 17,68 17,51 15,27 16,22 15,93 15,51 12,69 14,30 16,08

SST multiannual average 15,07 15,48 15,59 16,41 17,78 17,69 17,57 17,43 15,14 16,12 15,83 15,44 12,50 13,94 15,86

From the study Black Sea temperatures may buck the global trend of The Joint Research Centre (JRC) – The European Commission’s of Science and Knowledge Service, we have drawn some very interesting conclusions regarding the thermohaline regime and the evolution of the Black Sea current system in the 1960–2015 period: The Black Sea has unique natural conditions like a positive net freshwater balance and very specific local currents. Observational data on temperature change are varied and scarce. As such it is not clear what the impacts of climate change have been on Black Sea water temperatures. The simulations in this study, covering five decades, show no significant long-term trend in the Black Sea’s average surface

7.2 The Black Sea Thermohaline and Density Regimes

225

19 18 17 16 15 14 13 12 11

2016

2017

2018

2019

Average

Fig. 7.14 Black Sea ports SST multiannual average, 2016–2019 16,44

16,5

16

16,08 15,69

15,86

15,5 15,22 15 14,5 2016

2017

2018

2019 Average

SST mulannual average 2016-2019

Fig. 7.15 Black Sea coast SST multiannual average, 2016–2019

water temperature. It was also surprised to find a significant decreasing trend in the surface salt content of 0.02% per year, again in direct contrast to the increasing surface salinity found in the Mediterranean. The study identifies three distinct periods in which there was a significant shift in the saltwater and temperature properties of the Black Sea—1960–1970, 1970–1995, and 1995–2015. This may be related to changes in the Sea’s currents, as the periods were also characterized by significant changes from a weak and disintegrated current circulation in the first

226

7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.8 Black Sea coast SST, February 2016–2020, in  C Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Evpatoria Odesa Zatoka Black Sea coast SST ave rage

2016 6.0 6.8 6.8 8.4 9.7 9.6 9.6 9.7 6.4 8.9 8.5 7.7 3.0 3.6 7.48

2017 3.2 4.1 4.6 6.3 8.2 8.4 8.7 8.6 5.5 8.3 7.9 6.7 1.5 2.2 6.01

2018 5.8 6.6 6.6 8.4 10.3 10.3 10.2 10.3 6.3 9.1 8.8 7.7 3.6 4.4 7.74

2019 5.0 6.0 6.1 8.1 9.5 9.8 10 9.9 6.4 9.4 9.3 8.2 3.1 3.7 7.46

2020 7.3 7.8 7.7 8.9 9.7 9.8 9.6 9.6 6.3 8.9 8.6 7.6 5.4 5.9 8.08

Average 5.46 6.26 6.36 8.02 9.48 9.58 9.62 9.62 6.18 8.92 8.62 7.58 3.32 3.96 7.36

2019 15.2 16.1 16.3 16.3 17.6 17.7 17.7 17.8 17.6 15.8 15.2 16.2 16 15.7 16.51

2020 13.9 14.6 15.5 15 16.3 16.8 16.5 16.8 15.6 14.6 14.1 14.6 13.6 13.8 15.12

Average 15.78 16.18 1642 15.88 17.10 17.38 17.22 17.38 16.96 15.92 15.44 15.86 15.56 15.64 16,34

Table 7.9 Black Sea coast SST, May 2016–2020, in  C Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Evpatoria Odesa Zatoka Average—Black Sea coast

2016 15.6 16 16.2 16.6 16.9 17.1 17 17 17.1 15.8 15.6 15.9 15.5 15.8 16.29

2017 15 15.1 15.6 15 15.5 15.7 15.6 15.7 15.7 15 14.6 14.9 14.2 14,2 15.13

2018 19.2 19.1 18.5 16.5 19.2 19.6 19.3 19.6 18.8 18.4 17.7 17.7 18.5 18.7 18.63

period to a strong main “Rim Current” circulation in the second and third periods (Fig. 7.20) [13]. At present, SST values are daily measured with modern specialized satellites and are the basis for oceanographic analyzes and forecasts (Fig. 7.21a, b) [14].

7.2 The Black Sea Thermohaline and Density Regimes

227

Table 7.10 Black Sea coast SST, August 2015–2019, in  C Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Evpatoria Odesa Zatoka Average—Black Sea coast

2015 25.3 25.6 25.8 26 27.4 27.6 27.4 27.6 25.1 25 25.1 24.9 24.2 24.6 25.83

2016 25.4 25.5 25.7 26 27.3 27.5 27.6 27.6 26.6 26.2 25.8 25.6 24.2 24.7 26.12

2017 25 25 25.1 25.3 27.4 27.5 27.6 27.6 25.7 24.8 24.9 24.9 24 24.9 25.69

2018 26.2 26.3 26.3 26.1 26.7 27.2 27.4 27.2 25.1 25.3 25.4 25.3 25.6 26 26.15

2019 24.5 25.5 25.7 24.5 25.8 26.1 25.8 26.1 24.3 24 24 24 23.5 23.7 24.82

Average 25.28 25.58 25.72 25.58 26.92 27.18 27.16 27.22 25.36 25.06 25.04 24.94 24.30 24.78 25,72

2018 13.6 14.6 14.9 16.1 18.1 18 17,6 17.7 12.7 15.4 15 14.2 11.6 12.3 15.13

2019 15.1 16.5 16.7 17.4 18.1 17.7 17 17.5 13 15.3 15.2 14.5 13 13.6 15.76

Average 13.38 14.40 14.64 16.02 17.12 16.80 16.38 16.60 11.98 14.32 14.14 13.54 11.50 11.90 14.48

Table 7.11 Black Sea coast SST, November 2015–2019, in  C Port Constanţa Varna Bourgas Zonguldak Batumi Gagra Tuapse Sochi Kerch Yalta Sevastopol Evpatoria Odesa Zatoka Average—Black Sea coast

7.2.1

2015 13.3 14.3 14.3 15.7 16.5 16.2 15.8 16 11.3 13.9 13.9 13.5 11.9 11.8 14.17

2016 12.2 13 13.5 15.5 16.4 16.1 15.8 16 11.2 13.5 13.1 12.6 9.9 10.2 13.50

2017 12.7 13.6 13.8 15.4 16.5 16 15.7 15.8 11.7 13.5 13.5 12.9 11.1 11.6 13.84

The Ice Regime in the Black Sea

Generally, the ice occurs in the north-western part of the Black Sea, near the shore, and the frequency of days with ice has an average of 80 days/year at the mouth of the Dnieper (i.e., from 30–40 to 100–110 days/year, depending on the action of the cold wind), in Odesa Bay from 40 to 100 days/year during the cold winters (not during mild winters), in the Kerch Strait area 40–80 days/year, depending on the action of

228

7 The Specific Hydrological Factors of the Black Sea Basin

12 10 8 6 4 2 0

2016

2017

2018

2019

2020

Fig. 7.16 Black Sea coast SST multiannual average, February 2016–2020 20 19 18 17 16 15 14 13 12

2016

2017

2018

2019

2020

Fig. 7.17 Black Sea coast SST multiannual average, May 2016–2020

the cold wind (1–5 days/year during the mild winters) [7]. The most severe conditions are in Karkinit Bay, where the water freezes every year. Also, Danube, Dniester, and Dnieper form ice in their shedding areas even in the mild winters. The period of ice persistence is generally from December to February, depending on the particular area’s aspects (Fig. 7.22). To draw a picture closer to the reality of the ice regime in the Black Sea, it should be noted that in the last 120 years, in this area, the frequency of different types of the winter season was as follows: 15%—severe winters, 35%—moderate winters, and 50%—mild winters. The ice thickness is 0.3 m in the northern Black Sea sector (0.2 m in the Kerch Strait area), the maximum thickness of 0.6–0.7 m being in the severe winters, and the maximum extension (respectively, for February) is from Novorossiysk north, west, and south coast to

7.2 The Black Sea Thermohaline and Density Regimes

229

28 27 26 25 24 23 22

2015

2016

2017

2018

2019

Fig. 7.18 Black Sea coast SST multiannual average, August 2015–2019

20 19 18 17 16 15 14 13 12 11 10

2015

2016

2017

2018

2019

Fig. 7.19 Black Sea coast SST multiannual average, November 2015–2019

Eregli (Fig. 7.23). Also, in the figure, the ice concentration (5/10–7/10, and 8/10–10/ 10) is presented [15, 16, 17, 18].

7.2.2

The Thermohaline and Density Regime of the Black Sea Waters

Being characterized by a brackish salinity regime, the Black Sea presents lower values of salinity than 24‰ calculated on the entire mass of water, with very low

230

7 The Specific Hydrological Factors of the Black Sea Basin

Fig. 7.20 Climatological model surface circulations in February: (a) for 1990–1995 and (b) for 1995–2000, modified from public picture. The color bar represents the surface current speed, while arrows show both speed and direction. (Public pictures from JRC [13])

Fig. 7.21 (a) Black Sea SST Jan 15 , 2020; (b) Black Sea SST, Jan 15 , 2020–Jul 30, 2020. (Modified from public picture [14])

values in the front of the rivers’ mouths from the north-western sector. The surface layer of the seawater has a salinity medium value of 18‰, the depth layer salinity is over 24‰. In summer, the salinity is 15–17‰ (from 6‰ to 7‰ in the rivers’ mouth area from the north-western part of the Black Sea basin to 19‰ and even 23‰ in the open sea areas), and in the winter season, the salinity is lower by 0.5–0.6‰ towards the values recorded in the summer season due to the lower intake of freshwater during this time of the year. Also, as a result of lower salinity, the density of the Black Sea waters has low-value levels, i.e., generally below 1.0180. Up to the depths of 50–70 m, the density of the seawater depends on the temperature variations, and at depths higher than 70 m, it only depends on salinity because, as it was noted above, the temperature variations are not significant for the middle and deep water layers. The water density values vary with depth: up to 70–100 m depth, the water density is between 1.0144–1.0147, over 100–125 m depth is 1.0115–1.0157, 1.0171–1.01725 at 1,000 m depth, and 1.01725–1.01740 [16] at 2,000 m depth, respectively. The seasonal variation of water density is as follows: at the surface, 1.0106–1.0109 during the summer season and 1.0171–1.01725 in winter. On the

7.2 The Black Sea Thermohaline and Density Regimes

231

Black Sea Ukraine KHERSON ODESSA

Early Januaryearly February

CHORNOMORS’KE

Russian Federation

KERCH SULINA

Early Decemberearly February

Romania

Crimea YALTA

Early Januaryearly February

CONSTANŢA

Early Decemberearly February

NOVOROSIYSK

TUAPSE

ADLER

Bulgaria VARNA

Georgia

BURGAS

ISTANBUL AIRPORT

BATUMI

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.22 Average periods of ice formation in the Black Sea

Black Sea Ukraine KHERSON ODESSA

SULINA

8/10 -10/10 ice sea concentration 5/10 -7/10 ice sea concentration

CHORNOMORS’KE

Russian Federation

KERCH

Crimea NOVOROSIYSK

Romania

YALTA

CONSTANŢA

TUAPSE

ADLER

Bulgaria VARNA

Georgia

Maximum extend of ice sea more than 1/10 BURGAS

ISTANBUL AIRPORT

BATUMI

ZONGULDAK

Turkey

SAMSUN TRABZON

Fig. 7.23 Average maximum ice extent in the Black Sea, February

232

7 The Specific Hydrological Factors of the Black Sea Basin

Fig. 7.24 (a) Climatological mean SSS for 2005–2015 based on CMEMS data assimilation model - Copernicus Marine Environment Monitoring Service (modified from public picture - CMEMS, http://marine.copernicus.eu). (b) Calculated herein climatological mean SSS for 2005–2015. (c) SSS in July 1992. (d) Simulated climatological mean February SSS for 1993–2012. (By courtesy of Prof. G. Miladinova [10])

open sea, the density has higher values, the strata being more homogeneous. The izopycne of 1.014 stands at surface strata and that of 1.016 at the 90–160 m water depths. As a result of the density distribution of the water layers, in the central areas of the sea, the bottom convection phenomenon occurs, which produces the mixture of the bottom water masses with the other water masses situated at about 800–1000 m depths [18]. Recent research (Miladinova et al. 2017) about the Sea Surface Salinity (SSS) in the Black Sea shows that: the salinity difference between the North-Western Shelf and the rest of the basin (Fig. 7.24a) exists. For the same period (Fig. 7.24b) shows the presence of an inner shelf front, associated with the freshwater inflow from large rivers on the shelf. A salinity of about 18 ‰ establishes an interface between the interior waters and those mixed with the river waters. In Fig. 7.24c is plotted the mean SSS in July 1992. Figure 7.24d represents the 20-year SSS climatology in February from 1993 to 2012. The river waters extend down to the Bosphorus entrance region, in the form of a narrow coastal belt of current with salinities less than 14‰. The highest SSS is calculated in the centers of the main gyres and in the south-eastern part about 40 E and 42 N [10]. The Thermohaline Regime and Density of the North-Western Part of the Black Sea Basin In the north-western Black Sea basin, the physical characteristics of the marine waters depend on the local hydrographical conditions (e.g., major river inputs, shallow depths, specific thermohaline stratifications). From a general hydrological point of view, we must mention that the thermic regime presents significant seasonal

7.2 The Black Sea Thermohaline and Density Regimes

233

variations into the active layer of the sea, with the depth between 0 and 75 m, the thermic oscillations being reduced below this depth’s range. The water density also presents significant fluctuations in comparison with the above-mentioned factors’ variation. In the continental shelf marine waters from the north-western Black Sea, the temperature and density must be analyzed by some quantitatively determined gradients, in different areas of the sea and at different time intervals, respectively. The knowledge of the temperature and density gradients, in the final analysis, is interpreted by establishing the thermohaline and density structures. We consider this particularly important for the Black Sea, specifically by influencing navigation and marine activities. Undoubtedly, the greatest importance is the knowledge of the water layer having important vertical thermic variations (thermocline), as well as the layer having high-density variations (pycnocline). Before presenting the details of such depth layers position, and their importance in the water masses from the north-western Black Sea, we consider necessary the initial presentation of the monthly averages, i.e., the temperature and density gradients (γt, γσ) in a central point of the Romanian continental shelf, i.e., on the 50 m isobath for the standard depth of 0, 5, 10, 25, 50 m (Table 7.12, processing using data from [19]. The Temperature of the Marine Waters on the Continental Shelf of the Romanian Black Sea Sector The daily observations made in Sulina and Constanța ports referring to the temperature, as well as the standard hydrological profiles made on the open continental shelf in the last 10–15 years, have led to some conclusions as regards the seawater thermic conditions. Along the Romanian coastline, there is a good reflection of the environmental influences on the thermic regime of the sea surface waters. The data used showed a good correlation between the air and water temperature, but also a certain discrepancy—a lower water temperature during the spring months, a higher one during the autumn-winter seasons, towards the air temperature—due to the thermic retentivity of the marine waters. Some thermic differences were also recorded along the northern and southern coast: in Constanța and Mangalia, from March to August, the average water temperature is lower than the air temperature, while at Sulina, this difference is maintained for a relatively short period (May– August). The yearly average temperature of the surface seawaters is 12.7  C near the coast, exceeding the annual average temperature of the dry air by around 1  C. Without going into details, some clarifications regarding the surface temperature near the shore are required (the data presented below are from the marine hydrological stations, located along the Romanian coast). The data are as follows: – High temperatures averages: 23.1  C at Sulina and 22.4  C at Constanța, with extreme values that can exceed 28  C.

234

7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.12 The temperature gradients (A) and density (B) in the north-western part of the Black Sea Month Layer, m 0–5 5–10 10–25 25–50 Month Layer, m 0–5 5–10 10–25 25–50 Month Layer, m 0–5 5–10 10–25 25–50 Month Layer, m 0–5 5–10 10–25 25–50

I 0,12 +0,10 +0,05 +0,02

II +0,02 +0,02 +0,04 +0,04

III 0,00 0,00 0,00 0,00

IV 0,02 0,02 0,00 0,00

V 0,02 0,64 1,13 1,20

VI 0,20 0,18 0,50 0,10

VII 0,00 0,46 0,68 1,12

VIII 0,00 0,22 0,18 0,50

IX + 0,04 0,04 0,04 0,53

X 0,00 0,00 0,52 0,44

XI +0,06 +0,02 +0,05 0,26

XII +0,12 +0,08 +0,07 0,00

I 0,00002 0,00004 0,00001 0,00001

II 0,00004 0,00000 0,00001 0,00001

III 0,00000 0,00001 0,00004 0,00001

IV 0,00018 0,00004 0,00002 0,00002

V 0,00026 0,00002 0,00008 0,00009

VI 0,00016 0,00140 0,00025 0,00000

VII 0,00004 0,00026 0,00018 0,00003

VIII 0,00004 0,00002 0,00008 0,00009

IX 0,00002 0,00000 0,00004 0,00009

X 0,00002 0,00006 0,00003 0,00008

XI 0,00008 0,00002 0,00002 0,00005

XII 0,00002 0,00000 0,00000 0,00001

– Low temperatures averages: 1.9  C at Sulina and 2.9  C at Constanța, the absolute minimum values may exceed 0.90  C, the freezing point at 18‰ salinity (1.3  C); it must be noted that, at this point, in some winters, the coastal waters temperatures do not fall below 4  C and they can even reach an average value of over 8  C. As a result of the specific heat and the factors that determine the heating and the cooling of the coastal waters, it was ascertained that the increasing water temperature amplitudes have a maximum value during the summer season, a minimum one during the winter season, while, on the contrary, the air temperature amplitudes are minimal in summer and maximum in winter. Also, perturbations occur in the thermic factor evolution of the coastal marine waters, especially as a result of the atmospheric circulation, too. Thus, the western and south-western winds move the superficial layer waters towards the open sea, their place being taken by the deepness and saline, therefore denser waters, and significant changes in the normal course of the temperature that is called “upwelling” being produced. This effect especially occurs during the summer, when, at the shore, the water temperature significantly decreases, to values 100 m. In Table 7.14, it can be noticed that the caloric values during summer can be almost 2.5 times higher compared to the first months of the year. We also notice the relatively high values in November, in connection with the thermophysical properties of the marine waters in the last months of the year, with the good thermic convection and turbulence homogenization.

240

7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.15 Average temperature gradients (γt) and average density gradients (γσ) between 0 and 75 m depth Month γ ðt, σ Þ ΔH, m 0–5 5–10 10–25 25–50 50–75 Month γ ðt, σ Þ ΔH, m 0–5 5–10 10–25 25–50 50–75 Month γ ðt, σ Þ ΔH, m 0–5 5–10 10–25 25–50 50–75

II

III

IV

+0,010 +0,008 0,003 +0,002 0,026 V

0,002 +0,006 0,003 +0,005 +0,017 VI

+0,266 0,045 0,203 0,033 +0,023 VII

+0,012 +0,012 +0,005 +0,006 +0,004

0,307 0,158 0,032 +0,010 –

– – – – –

0,164 0,140 0,085 0,280 0,000 VIII

+0,039 +0,044 +0,024 +0,011 +0,010 IX

0,167 0,323 0,555 0,089 +0,011 X

– – – – –

0,195 0,278 0,508 0,097 0,029

+0,138 +0,116 +0,136 +0,015 +0,012

+0,026 0,000 0,101 0,417 0,067

0,016 +0,014 +0,015 +0,099 +0,006

+0,008 0,203 0,047 0,455 0,022

– – – – –

+0,030 +0,010 +0,001 0,115 0,036

0,040 0,011 0,008 +0,137 +0,013

(d) Particularities of the Thermic and Density Regimes, Expressed by Gradient Variations off the Romanian Shelf Using temperature and density data of the Romanian continental shelf, at the 50 m isobath, obtained from annuals and oceanographical atlases, as well as from the recent works and measurements, the vertical and seasonal variation of the average temperature and density gradients in the period 1997–2010 has been shown (Table 7.15). The gradient values present the sign (+) or () related to the increase or decrease of the temperature, the density variation, respectively. In the data processing, the gradients values for the months January–December are not included because, in this period, the number of the field measurements on the sea was very limited [22]. Considering the large variations, especially of the temperature gradient and its importance, we present the extreme values () of the temperature gradients (Table 7.16), as well as the diagram of the seasonal variation, γt (Fig. 7.27), to establish the variation difference of this parameter. In Table 7.16, as well as in Fig. 7.27, we can notice the domination of the negative thermic gradients, especially during the summer season (which means the high

7.2 The Black Sea Thermohaline and Density Regimes Table 7.16 Extreme values of the temperature gradient in the offshore waters of the Romanian shelf

Month γ ΔH, m +γt ΔH, m γt Month γ ΔH, m +γt ΔH, m γt

241

II

III

IV

V

VI

5–10 0,188 0–5 0,196 VII

0–5 0,128 0–5 0,070 VIII

25–52 0,025 0–5 0,960 IX

50–75 0,079 0–5 0,728 X

50–65 0,039 0–5 0,355 XI

0–5 0,074 10–20 0,985

50–75 0,075 20–30 0,918

75–100 0,028 25–50 0,592

0–5 0,064 30–50 0,366

0–5 0,144 35–50 0,249

0,4 0,2 0 -0,2

II

III

IV

V

VI

VII

VIII

IX

X

XI

-0,4 -0,6 -0,8 -1 -1,2 Posive temperature gradient

Negave temperature gradient

Fig. 7.27 Extreme values of the temperature gradient in the offshore waters of the Romanian continental shelf

thermal stratification also corresponds with a slight positive density gradients domination within the entire year). Also, the data in the table indicate the immersion position where the extreme values γt have been found. Thus, it can be shown that, at the Black Sea shore, the sea waters’ density varies between 1000 (at the Danube’s mouths) and 1015 (offshore), with well-determined and relatively stable vertical stratification. The vertical stratification of the waters from the Romanian shore restrains the water’s mixing process with depth. Therefore, warming and cooling are limited at a depth of 50–100 m (Fig. 7.28). In Mihailov et al.’s (2016) opinion: the annual average temperature in the Romanian Black Sea area is 12.0–14.0  C, exceeding by 2–3  C that of the air. During winter, the seawater temperature often drops below 1  C in the near-shore zone. In the very cold years, ice of 15–20 cm thickness can form at the shoreline. In May, the surface water temperature reaches an average of about 13.0  C near the shore and 20  C in the central part of the shelf. Sensible decreases in temperature

242

7 The Specific Hydrological Factors of the Black Sea Basin 0

10

11

12

13

14

15

16

17

18

Sea Water Density

10 15 summer

75 125

winter

1000

2000 H(m)

Fig. 7.28 Vertical stratification of the sea waters at the Romanian littoral. (Processed after Şelariu, 1999)

occur since the beginning of September. The strong summer heating affects only the upper 10–30 m of the active layer, the sea surface temperature rising above 25  C, while only minor variations of the parameters occur in the Cold intermediate layer (CIL). For the central part of the shelf, the surface water temperature increases by about 0.1  C/year during the 1971–2010 period. The change at mid-depth (30 m) is less of half of that value (~0.03  C/year), while at the bottom, the average temperatures are practically constant. By contrast, the salinity values decrease by approximately 0.03 PSU/year in the entire water column, except for the surface, where it changes by only 0.02 PSU/year (Fig. 7.29) [23].

7.2.3

The Hydrodynamics of the Black Sea Waters: Level Oscillations, the Waves, and Marine Currents in the Black Sea

The marine hydrosphere is in permanent dynamics and generally distinguishes by the next movement categories: translation movement, e.g., the marine currents;

7.2 The Black Sea Thermohaline and Density Regimes

243

Fig. 7.29 Annual evolution of the sea temperature ( C) and salinity (PSU) at the Offshore Constanţa stations, 1971–2010 [23]. (By courtesy of Dr. M. Mihailov)

convection currents, e.g. the vertical movements of the sea surface; and undulatory movements which differ depending on the oscillation period. Generally, by marine agitation, we understand the degree or the sea state, which, in the last analysis, depends on the wind waves’ height and swell. The Black Sea’s Levels Under the effect of multiple factors, the Black Sea surface is permanently subject to some vertical, periodical, or nonperiodical oscillations. The level oscillations can be of: volume, caused by the water quantity variation, and deformation, caused by the shape variation of the sea free surface. Being independent of each other, the level oscillations are produced by the following factors: climatical (precipitations, evaporations); hydrological (flowing waters influx, the water exchange through the Bosphorus, and Kerch straits); cosmic (tides); and meteorological (level oscillations caused by the wind and seiches, because of the atmospheric pressure variation). The Black Sea is individualized by the regular level oscillations, with a maximum value during the summer season and a minimum in the cold season of the year. The level increases gradually starting with December to a maximum in July; then it gradually decreases to the minimum in November. The moment of the maximum sea level is less stable, because in 70% of the cases, this occurs in June, rarely in July, and exceptionally in August. The moment of the minimum sea level is less stable (in 30% of the cases in January, 23% in October, 20% in November, and rarely in March and December). The average amplitude of the level oscillations, caused by the water volume variations, reaches values of 20–28 cm. The deformation oscillations are determined by the meteorological and cosmic factors, and their periods and amplitudes depend on the physical-geographical conditions (the depth, the underwater relief, and shoreline configuration). Depending on the period, the level oscillations can be of the following types: – Small duration oscillations (diurnal oscillations), directly obtained and daily observed through the registering tide gauge or using the hydrometer – Long duration oscillations (monthly and annually oscillations), highlighted as monthly level averages (caused by seasonal variations during a year) and as annual level averages (caused by multiannual variations)

244

7 The Specific Hydrological Factors of the Black Sea Basin

– Very long duration oscillations (centennial oscillations) caused by the slow change of the climate and geological processes (slow tectonic movements) The small duration oscillations of the sea level are determined only by the winds, seiches, and tides. Because of the air friction at the sea surface, the winds in the Black Sea put in motion the water layer up to a depth of 50 m, having, as a result, the forming of the marine drift currents. The winds which blow from the sea cause the water level to rise at the coast and, conversely, blowing from the land, they decrease the water level at the coast. The seiches are a periodical oscillations phenomenon (i.e., of attenuation or assertion) of the sea level produced by a series of causes, such as sudden stop of the wind, the passing of the cyclones, or atmospherical fronts over the sea surface. The seiches periods in the Black Sea vary from a few minutes to 13 h, respectively the amplitude from a few centimeters to 2 m (in exceptional cases). In the Black Sea, the tide has insignificant values for navigation, i.e., a maximum of 10 cm. In conclusion, it can be stated that the Black Sea’s level is of relative growth, by 0,1–12,2 mm/year [20]. The water level fluctuations depend on the winds’ speed and direction, the shores’ shape and nature, the sea's bottom topography, respectively, the following: in the mountainous shores, the increase is 0.2–0.3 m towards the waters’ “0” levels. In the Crimean Peninsula it is between 0.4–0.9 m (the maximum value, i.e. between 1.8–2.1 m, is in the Kerch Strait and Kalkinik, Tendra, and Egorlâk gulfs), at the Romanian shore, 0.5–0.7 m [23]. Long Duration Oscillations In the Quaternary, the Black Sea oscillations were characterized by a succession of increases and decreases. At present, it is considered that the Black Sea is in the process of transgression, but that must be seen in the context of the oscillatory character of the sea level for large periods. According to the calculus done by O. Șelariu (1972), the increasing tendency is 25.95 cm per century in Constanța and 33,90 cm in Sulina. The research as regards the morpho-hydrological changes over the accumulation shore has established that the sea level varied (in average annual values) from 1.53 cm (1943) to +29.7 (1970), with a range of 31.2 cm and an increasing general trend, superimposed over a cyclic variation [24]. Considering that the descending speed of the terrestrial crust is 1,19 mm/year, comparing the geodetic landmark from Constanța (e.g., No. 168, Tomis Bvd.) and the Constanţa tide gauge, it results in a level difference of 27,9 mm (0,75 mm/year); therefore, the sea level increasing was of approximately +1.38 mm/year after the regression line and +1.44 mm/year after the regression curve, i.e., of approximately 5 cm in the 1930–1980 period [24]. The highest multiannual amplitudes of the sea oscillations do not exceed 2 m (exceptions are Mykolaiv port and the riverine ports that have 1 m) [25]. Recent research on the evolution of the Black Sea level reveals its concrete values determined for different time series, as follows:

7.2 The Black Sea Thermohaline and Density Regimes

245

Table 7.17 The trends of sea-level variations at some tide-gauge stations in the Black Sea Tide-gauge station Igneada Amasra Trabzon II Batumi Poti Tuapse

Country Turkey Turkey Turkey Georgia Georgia Russian Federation

Time-span 2002–2009 2001–2009 2002–2009 1982–2013 1974–2013 1917–2011

Trend (mm/year) 6.33  3.97 0.62  2.01 6.60  3.96 1.97  0.08 6.65  0.07 2.41  0.11

– Boguslavsky et al. 1998, using empirical observations, during this century, against the background of broad spectral oscillations, the Black Sea mean level is rising at the rate of 1.6 mm year1 [26]; – Goriacikin and Ivanov (2006) in their book show that the mean multiannual Black Sea level, between 1923 and 1993, calculated based on measurements from 14 hydrometric stations on the northern coast, is 477 cm in the GVO altimetry system of the former USSR: annual mean Black Sea levels depend upon the water volumes from tributary rivers. During the 1946–1985 time interval, the average trend of the mean annual sea-level rise was found to be about 2.7 mm/year. By eliminating the vertical movement speed of Earth’s surface, a mean rate of sea-level increase of about 1.7 mm/year, due to eustatic factors, resulted. The Crimean coast is sinking by about 0.2 cm/year; in Odesa, by about 0.51 cm/year; and in Poti, by about 0.65 cm/year. Average subsidence in the Black Sea basin is evaluated at about 0.1 cm/year, except for the Odesa and Poti sites. Based on long-term monitoring of the Black Sea level data, the subsidence is evaluated at 0.03–0.16 cm/year. In Odesa and Poti, the subsidence is of 0.52 and 0.66 cm/ year, respectively. By processing a long series of Black Sea level measurements in Poti, in Odesa, and in Constanţa, it is showed that the subsidence values are 0.56, 0.43, and 0.35 cm, per year, respectively. The most significant Black Sea level change in time is located at Varna and at Burgas, where, in the 1928–1980 interval, it reached 1.07 and 0.73 cm/year, respectively, which represents the highest value of crust subsidence [27]; – Avşar et al. (2015), using the satellite altimetry data, show an accelerated rise in sea level of 3.19  0.81 mm/year for the period of 1993–2014. Although the geographical distribution of the Black Sea level variation rate is mostly uniform, it is detected bigger than the mean in the southeastern part (Table 7.17) [28]. – Avşar et al. (2018) show that the present-day sea-level change in the Black Sea estimated from satellite altimetry and gravity measurements demonstrate that the Black Sea level has risen at an average rate of 2.5  0.5 mm/year from January 1993 to May 2017. During this period, inter-annual variability of the nonseasonal sea-level change is quite strong. Furthermore, mass contribution to this change for the period 2002–2017 has been detected as 2.3  1.0 mm/year from the Gravity Recovery And Climate Experiment (GRACE) mascon solutions [29].

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7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.18 Trend and seasonal components of coastal (relative) sea-level changes at the tide gauge stations along the Black Sea coast [29]

Tide gauge station

Annual amplitude (mm) Amplitude (mm) 78.14  6.55

Phase ( ) 127.94  0.08 152.73  0.09

Amplitude (mm) 15.74  6.55 27.38  6.41

Phase ( ) 26.34  0.42 344.06

141.78  0.12 130.14  0.23 128.86  0.20

20.84  8.12 16.01  11.22 22.90  12.84

19.83  0.39 50.66  0.70 49.11

30.69  5.71

104.70  0.18

3.47  5.66

340.66

49.04  11.26

135.82  0.23 153.45  0.14 158.48  0.06 157.76  0.05 142.41  0.06 139.65  0.06

29.53  11.28 27.09  8.93 35.19  4.43 35.86  4.05 37.00  3.85 30.07  4.59

12.06  0.38 17.09  0.33 22.01  0.13 26.52  0.11 29.78  0.10 16.25  0.15

Data period Jan. 1945 Dec. 1979 Jan. 1926 Nov. 1961

Trend (mm/year) 3.02  0.46 1.53  0.48

Feb. 1981 Jan. 1996 Jun. 2002 Dec. 2014 Jul. 2008 Dec. 2014

7.52  1.33 6.94  2.18 5.03  4.84

67.23  8.13

Amasra

Jun. 2001 Feb. 2011

3.43  1.42

Sinop

Jun. 2005 Dec. 2014 Jul. 2002 Dec. 2014 Jan. 1925 Dec. 1996 Aug.1922 Dec. 2002 Jan. 1943 Dec. 2011 Jan.1925 Dec.1996

0.43  2.88 2.33  1.75 3.52  0.15 7.01  0.12 2.92  0.14 1.56  0.22

Varna

Burgas Igneada Şile

Trabzon Batumi Poti Tuapse Sevastopol

Semiannual (mm)

69.54  6.42

49.16  11.17 62.92  12.84

62.77  8.93 78.93  4.43 77.42  4.05 70.42  3.85 79.41  4.58

 0.23

0.56  1.63

– Avşar and Kutoglu (2020), present the trend and seasonal components of coastal (relative) sea-level changes at the tide gauge stations along the Black Sea coast (Table 7.18 and Figs. 7.30, 7.31, and 7.32) [30, 31] The land subsidence motions at the Tuapse, Varna, Trabzon, and Şile are shown in Table 7.19. Land uplift motions were seen at the Burgas and Sinop. Especially for Şile, the high relative sea-level rise may result from the land subsidence [32]. The mean rate of the sea level rise has been estimated as 2.5  0.5 mm/year over the entire Black Sea by using the gridded satellite altimetry data covering January 1993–May 2017. During this period, it was seen that inter-annual variability of nonseasonal sea-level change was quite strong (with a standard deviation of about 6.7 cm). Note that the dominant cycles of sea-level change indicate that the Black Sea rose at a rate of about 3.2  0.6 mm/year until December 2014. This rate was

7.2 The Black Sea Thermohaline and Density Regimes

247

5,03 3,02

10

7,01

6,94 3,43

1,53

2,33

3,52

2,92

0,43

1,56

5 0 -5

-7,52

-10

Treand of coastal sea level changes (mm/year)

Fig. 7.30 Trend and seasonal components of coastal (relative) sea-level changes at the tide gauge stations along the Black Sea coast

Legend Trend (mm/year) Annual Amplitude (mm)

Constanta

3.02 ± 0.46 78.14 ± 6.55

1.56 ± 0.22 79.41 ± 4.58

Black Sea

1.53 ± 0.48 69.54 ± 6.42 −7.52 ± 1.33 67.23 ± 8.13

Igneada 6.94 ± 2.18 49.16 ± 11.17 Sile

Tuapse

2.92 ± 0.14 70.42 ± 3.85

Varna

Bourgas

Sevastopol

3.43 ± 1.42 30.69 ± 5.71

0.43 ± 2.88 49.04 ± 11.26

7.01 ± 0.12 77.42 ± 4.05 Poti

Sinop Amasra

5.03 ± 4.84 62.92 ± 12.84

2.33 ± 1.75 62.77 ± 8.93

3.52 ± 0.15 78.93 ± 4.43 Batumi

Trabzon

Fig. 7.31 Annual amplitude

nearly identical to the global trend, which was reported by Legeais et al. (2018); this common tendency may be attributed to global warming [33]. The Waves of the Black Sea As a result of the various natural forces over the sea and the ocean waters, oscillating and translation movements of the water particles are produced. The propagation of the oscillations of the particles in the seawater, as well as in any deformable environment (e.g., solid, liquid, gaseous) is called wave movement, or, generally, waves. Also, by marine waves, we understand those forms of periodical movement,

248 78,14

7 The Specific Hydrological Factors of the Black Sea Basin

69,54

78,93 67,23

62,92

77,42

62,77

49,16

70,42

79,41 80 70 60 50 40 30 20 10 0

49,04 30,69

Annual Amplitude (mm)

Fig. 7.32 Black Sea western basin – waves average frequency depending on the sea state Table 7.19 Vertical land motions at some tide gauge locations along the Black Sea coast [30]

Tide gauge station Tuapse

GNSS station TUAP

Varna

VARN

Burgas

BUR3

Trabzon

TRBN

Sinop

SINP

Şile

SLEE

Data period Tide gauge 1943– 2011 1926– 1961 1981– 1996 2002– 2014 2005– 2014 2008– 2014

Distance (km) GNSS 2015–2017

Vertical velocity (mm/year) 0.05

2005–2017

2.1

2009–2014

1.5

2009–2014

2.8

2010–2014

0.8

2009–2014

1.2

1.7  0.5 1.1  0.1 4.2  0.2 1.9  0.3 6.2  2.5 3.0  0.6

continuously variable, where the water particles are making oscillatory movements around their equilibrium position. In the specialized literature [34], the wave classification is made depending on: – – – – – – – –

The causes that determine the oscillatory movement The action of the balancing forces The action of the forces that support the waves The fluctuation in time of the elements The disposing of the water layer where the waves act The waves’ shape The proportion between the waves length and the depth of the water reservoir The character of the movement of the waves

7.2 The Black Sea Thermohaline and Density Regimes

249

The phenomenon must be thoroughly studied because in the Black Sea basin, the wind imposes itself as the primary and significant agent in the propagation of a wave system at the water surface, the waves being generated by the wind. Depending on the formation and propagation conditions, the waves produced by the wind in the Black Sea are of the following types: – The wind waves that represent a system of waves situated in the observation moment and placed under the direct action of the wind that produces them and modifies their dimension and shape; in the deep water, the propagation directions of the wind waves, as well as the wind, usually coincide or differ with at the most 45 (four carts); the wind waves differ by the fact that the declivity under the wind is more abrupt than that one inside the wind and the tips of the apex are collapsing, resulting the foam or even breaking, in case of a strong wind; in case the wind waves reach the shallow bottom, or at the coastline, the propagation directions of the waves and the wind can differ with more than 45 ; the wind waves are higher during the winter and autumn seasons, when the winds from the sea are predominant; in the western basin of the Black Sea, the height of these waves is of 6–8 m, with a maximum value of 14 m; ashore, the value ranges from 4.3 m—Odesa value to 5.1 m—Tendre, 5.7 m—Sevastopol, 6 m—Constanța, and 8 m—on the mountainous shores; the waves energy varies depending on the area. – The swell waves is a system of waves left by the wind that stopped blowing, or that has changed the direction in the observation moment, or a system of waves produced by the wind that blows far from the observation zone; a particular case is a swell which propagates in the absence of the wind (e.g., the calm state), called dead swell; usually, the swell waves are longer than the wind waves, they are smooth and with an almost symmetrical shape; the propagation direction of the swell can differ more towards the wind direction, respectively, at the moment, in that observation place; often, the surge is propagated against the wind or perpendicular to its direction; – The overlapping waves, which are generated by the uniform and simultaneous presence of two or more wind waves systems, which interfere with each other. – The resac waves (Resaca), which can be observed when the wind or swell waves, propagated from the high seas, reach the shallow waters; in this case, the action of the water bottom changes the waves’ characteristics. First of all, we can observe the wave’s shape-changing, i.e., the three-dimensional waves are passing over a shallow water depth, and they are turning into two-dimensional waves. Therefore, the waves from the shallow waters are distinguished by very long crests, respectively, parallel to each other; and simultaneously, the waves propagation speed is changing along with the wave shape profile, height, and length. At the same time, the slope of the wave increases very much and the striking force, too. So, at the proximity of their coast, as the water depth decreases, the waves become steeper and shorter, and at a depth that is not exceeding the waves’ height, the crests are rolling and breaking. The Resaca is accompanied by the surface and bottom currents, oriented in opposition, and in the case of the steep bottom, it is

250

7 The Specific Hydrological Factors of the Black Sea Basin

accompanied by the waves interference phenomena (i.e., they are propagated from the high seas with the reflected ones). The high waves occur during the cold season (the frequency being 10% in some districts), and during the summer season, they are less frequent (3%). In the cold season, the 6 sea state and higher frequency represent over 10%, and 0 and 1 sea state is between 20% and 30%. The main direction of the wave propagation is north and north-east. The wave’s height during the winter storms can reach 5–8 m. In the transitional season, the wave regime is maintained alike during the winter season, but with an unstable propagation direction and sometimes with heights of 6–7 m. In the summer season, the six sea state and above frequency is 2%, the strong waves are formed from western to northern direction, with maximum heights of 6–7 m, respectively, but the predominant waves have about 1 m. During the transition to the cold season, the agitation of the sea remains similar to that in the summer season, and beginning with October and November, the sea degree of agitation increases, the 4 sea state and above reaching 5–10% in some regions; the main direction of the waves propagation is from north-east and east and sometimes from the south, having the maximum height of 6–7 m. Generally, the length of the waves in the Black Sea is between 30 and 50 m, with a periodicity of 6 s, but in the eastern and south-eastern regions, longer wind waves are frequently formed, i.e., of approximately 100 m, with a periodicity of 10–12 s, as well as the swell waves, having a length of 150–200 m, with a periodicity of 15–17 s. The waves average frequency, depending on the sea state in the Black Sea western basin (Table 7.20 and Figs. 7.33, 7.34, 7.35, 7.36, and 7.37) [1, 35], shows the following features: Russian scientists Arkhipkin et al., (2014) present the maps with the significant wave height, length, and period in all seasons (Fig. 7.38a–d) [36]. The calculated values of the significant wave height, length, and period in all seasons in the Black Sea basin present the following values: (a) In winter: – Significant wave height (SWH) varies between 0.4 and 0.9 m, with the minimum values in the north-western and south-eastern extremities and the maximum value in the central area of the basin. – Length (L ) varies between 4 and 9 m, with the minimum values in the northwestern and southeastern extremities and the maximum value in the central area of the basin, similar to the SWH evolution. – Period (P) varies between 2 and 2.8 s, with the minimum values in the northwestern and south-eastern extremities and the maximum value in the central area of the basin, similar to the evolution of SWH and L. (b) In spring: – Significant wave height (SWH) varies between 0.3 and 0.6 m, with the minimum values in the north-western and south-eastern extremities and the maximum value in the central area of the basin.

7.2 The Black Sea Thermohaline and Density Regimes

251

Table 7.20 Waves average frequency in the Black Sea western basin, depending on the sea state Sea area Western basin

North – eastern sector

South-eastern sector

Southern sector

Sea state 0–1 2–3 4–5 6–7 8–9 0–1 2–3 4–5 6–7 8–9 0–1 2–3 4–5 6–7 8–9 0–1 2–3 4–5 6–7 8–9

Months I 6 34 40 18 2 10 43 36 9 1 24 42 26 8 – 21 41 32 6 –

II 12 41 35 10 1 13 41 35 10 1 21 42 30 6 – 25 36 33 5 –

III 18 45 32 5 – 20 33 31 15 – 33 40 20 7 – 29 43 21 3 –

IV 27 57 15 1 – 28 46 21 5 – 45 43 11 1 – 41 45 14 – –

V 33 51 15 1 – 35 47 15 2 – 49 42 8 1 – 40 48 11 – –

VI 41 43 14 1 – 33 46 19 2 – 47 42 7 1 – 38 56 6 – –

VII 45 42 12 1 – 30 42 26 2 – 47 43 8 1 – 34 55 11 – –

VIII 25 54 20 1 – 25 46 25 4 – 43 45 10 1 – 32 58 10 – –

IX 26 47 23 2 – 28 47 20 4 – 35 48 15 2 – 32 49 29 – –

X 19 38 39 5 – 19 47 25 8 1 34 50 13 3 – 30 41 27 2 –

XI 15 37 36 11 1 20 52 25 2 1 35 51 13 3 – 28 43 25 3 –

XII 11 39 38 11 1 10 38 36 15 1 21 49 25 5 – 21 41 35 3 –

60 50

%

40 30 20 10 0 –12–34–5

6–7 8-9 0–1 2–3 4–5 6–7 8-9 0–1 2–3 4–5 6–7 8-9 0–1 2–3 North – Eastern sector 4–5 6–7 South-Eastern sector Southern sector

Western_basin

I

II

III

IV

V

VI

VII

VIII

IX

X

XI

I

Month

X VII IV

0

8-9

XII

Fig. 7.33 Black Sea western basin—waves average frequency depending on the sea state

– Length (L ) varies between 3 and 6 m, with the minimum values in the northwestern and south-eastern extremities and the maximum value in the central area of the basin, similar to the SWH evolution. – Period (P) varies between 1.8 and 2.2 s, with the minimum values in the northwestern and south-eastern extremities and the maximum value in the central area of the basin, similar to the evolution of SWH and L.

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7 The Specific Hydrological Factors of the Black Sea Basin

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Sea state 0 – 1

Sea state 2 – 3

Sea state 4 – 5

Sea state 6 – 7

Sea state 8-9

Fig. 7.34 Waves average frequency in the Black Sea western basin

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Sea state 0 – 1

Sea state 2 – 3

Fig. 7.35 Waves average frequency in the north–eastern sector

Sea state 4 – 5

7.2 The Black Sea Thermohaline and Density Regimes

253

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Sea state 0 – 1

Sea state 2 – 3

Sea state 4 – 5

Fig. 7.36 Waves average frequency in the south–eastern sector

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Sea state 0 – 1

Sea state 2 – 3

Fig. 7.37 Waves average frequency in the southern sector

Sea state 4 – 5

254

7 The Specific Hydrological Factors of the Black Sea Basin

Fig. 7.38 (a) Map of calculated average significant wave height SWH [m], (b) map of calculated average significant wave height SWH [m], wavelength L [m], and period P [s] in winter wavelength

7.2 The Black Sea Thermohaline and Density Regimes

255

(c) In summer: – Significant wave height (SWH) varies between 0.2 and 0.4 m, with the minimum values in the north-western and south-eastern extremities and the maximum value in the central area of the basin. – Length (L ) has a value of 4 m in almost the entire basin and values less than 4 m in coastal areas. – Period (P) has the value of 2 s in the central and southern part and with values of 1.8 s and lower in the north-western, northern, and south-eastern extremities. (d) In autumn: – Significant wave height (SWH) varies between 0.3 and 0.7 m, with the minimum values in the north-western and south-eastern extremities and the maximum value in the central area of the basin. – Length (L ) varies between 3 and 7 m, with the minimum values in the northwestern and south-eastern extremities and the maximum value in the central area of the basin, similar to the SWH evolution. – Period (P) varies between 1.8 and 2.4 s, with the minimum values in the northwestern and south-eastern extremities and the maximum value in the central area of the basin, similar to the evolution of SWH and L. Rusu et al. (2018) show that: compared to the large oceans, the Black Sea’s wave energy potential is lower due to the limited fetch of the basin. Contrary to the wave energy conditions, the wind power over the Black Sea basin can be considered significant in several zones, where the wind power is comparable to the most energetic locations of northwestern Europe [37] (Table 7.21, Figs. 7.39 and 7.40). Divinsky et al., in the article Extreme wind waves in the Black Sea (2020) present a complex analysis of the wind seas, mixed waves, and swell spatial distributions of the maximum waves in the Black Sea and provide evidence that favorable conditions for the development of storm waves with significant wave heights of about 12 m may develop in the Black Sea. This means that the real maximum waves can be as high as 18–19 m. Three regions are clearly distinguished from the wave potential. The time of manifestation of extreme situations is slightly different: in the southwestern part of the sea, extreme events usually occur in January and December; extreme events south of the southern coast of the Crimea Peninsula occur in February; while in the northeastern part of the sea, they appear in November. The southeastern and extreme eastern parts of the sea are most subjected to strong swell [38]. The distribution of maximum swell waves is different from the wind waves since the swell propagates beyond the zones of  ⁄ Fig. 7.38 (continued) L [m] and period P [s] in spring. (c) Map of calculated average significant wave height SWH [m], (d) map of calculated average significant wave height SWH [m], wavelength L [m], and period P [s] in summer wavelength L [m] and period P [s] in autumn. (Modified after Arkhipkin et al., 2014 [36])

256

7 The Specific Hydrological Factors of the Black Sea Basin

Table 7.21 The wind power over the Black Sea basin

Mean wind field Maxim wind speed (MWS) Mean significant wave height (Hsmax) 9

Period 1997– 2016 7.14 m/s

Winter (DJF) 8.24 m/s

Spring (MAM) 6.79 m/s

Summer (JJA) 6.12 m/s

Autumn (SON) 7.52 m/s

1.06 m

1.44 m

1.01 m

0.8 m

1.11 m

8,24 7,52

8 7 6

6,79 6,12

5 4 3 2

1,44

1,01

0,8

1,11

1 0 Winter

Spring MWS in m/s

Summer

Autumn

Hsmax in m

Fig. 7.39 Black Sea—maxim wind speed (MWS)

surface wave generation. The main regions of maximum swell waves are in the south-southwestern and eastern parts of the sea. The height of the swell usually does not exceed 6–7 m (Fig. 7.41) [38]. The Sea Currents in the Black Sea In oceanography, the sea currents mean the horizontal movement of the water masses, without taking into consideration the horizontal components of the velocity, which are small compared to the first ones. Thus, the last-mentioned components are only complicating the calculations. The streams direction is where the movement happens, and their speed is expressed in knots or cm/s (1 Kt ¼ 51.44 cm/s; 1 cm/s ¼ 0.01945 Kt). It should be taken into account that the displacement of the water masses occurs under the influence of various internal or external forces, which are variable in space and time and whose result is difficult to calculate or predict. However, starting from the laws of hydrodynamics and making a series of generalities and simplifications, we can reach some theoretical conclusions and put the application possibility into practice. The sea currents’ forming is in connection with the causes that, in the last analysis, can be of hydro-meteorological and astronomical type.

7.2 The Black Sea Thermohaline and Density Regimes

257

Fig. 7.40 Black Sea—mean significant wave height (Hsmax) [36]. Note: the spatial distribution of the mean wind fields (left panels) and the mean significant wave height fields (right panels) for the entire 20-year period 1997–2016 (first line) and each season: winter (DJF)—second line, spring (MAM)—third line, summer (JJA)—fourth line, autumn (SON)—last line. (By courtesy of Prof. L. Rusu [37])

In the Black Sea, the current regime is specific to the currents’ regime from an isolated body of water; this is determined by the winds regime, the river water intake, the water density variation, the seabed topography. All kinds of currents are formed, of particular importance being the influence of the resultant of the atmospherical circulation and the temporary winds, which creates drift and wind stationary currents. The current system appears as a closed system, with specific particularities in

258

7 The Specific Hydrological Factors of the Black Sea Basin

Fig. 7.41 Maximum wave heights possible once in the given number of years. (Modified after Divinsky et al. [38])

some areas. The main current includes all the big mainstream that forms a circle with a diameter of 20–50 nautical miles, at a distance of about 2–5 nautical miles from the shore up to depths of 1000 m. This area is characterized by stability and speeds between 0.5 and 1.09 Kt (2–3 Kt), during the action of strong winds. The movement runs in the counterclockwise direction, i.e., parallel to the shore, and rarely it has a reversed direction. In the central areas of the eastern and western basins of the Black Sea, the currents are circular, with a counterclockwise motion, a low and moderate speed, i.e., of 0.2–0.5 Kt. Inside the bays, circular currents appear, having the motion in the clockwise direction, with speeds of 0.2–0.5 Kt [37]. There are four major

7.2 The Black Sea Thermohaline and Density Regimes

259

Odessa

Kerch

Sulina

0.4-0.6

Sevastopol

Novorossiysk

0.4-0.6 Constanţa

0.8-1.0

0.8-1.2

0.8-1.2

0.8-1.2 0.4

0.8-1.2

Bourgas

Black Sea 0.4-0.6

Tuapse

0.4

Varna

0.2-0.4

0.4

0.2 0.8-1.0

0.2 0.8-1.2

Poti 0.8-1.2

0.8-1.2 0.8-1.0

Sinop

0.8-1.4

0.4 Batumi

Zonguldak Istanbul

Trabzon

Fig. 7.42 Marine currents evolution in the Black Sea—during the summer season, modified after Eremeev, 1993 using a free map support from https://d-maps.com/carte.php?num_car¼4447& lang¼en

branches of this cyclonic movement called: the current of Anatolia, the current of Caucasus, the current of Crimea, and the Rumel current (it gets a movement impulse from the rivers’ mouth from the north-west of the Black Sea, i.e., along the western shore, carrying the water masses from east to west and then to south). From Cape Sarich, the marine current has an orientation towards the north-west, to Cape Tarkhankut (the speed being 0.5–0.7 Kt). Inside the bays Feodosia and Kalamit, there are anticyclonic currents having speeds of 0.3–0.5 Kt. We also determined stable currents (the speed is between 1 and 3 Kt) at Cape Meganom, Sarich, Aia, Fiolent, and Kerson. On the eastern shore of the Black Sea, the current has a general direction to the north-west (the speed is between 0.5 and 0.7 Kt), and in the bays from here, we meet locally unstable currents (the speed is between 0.3 and 0.5 Kt). The currents from the southern shore of the Black Sea have an eastward movement (the speed is between 0.6 and 0.8 Kt), following the coastline configuration (inside the bays and at the capes, there are anticyclonic currents (the speed is between 0.3 and 0.5 Kt) [39]. Shortly, the currents from the Black Sea basin can be characterized as follows: in the cold season, in the entire basin, a cyclonic system with two centers is formed, respectively eastern and western, and with two secondary anticyclone centers, i.e., in the north-western and south-eastern parts. During the transitional period, the situation is opposite to that during the wintertime, but less developed. In the summertime, a cyclonic center is formed in the western part, while in the eastern part, an anticyclonic center in a weak depression, i.e., with an anticyclonic center in the north-west and a cyclonic center in the south-east (Fig. 7.42).

260

7 The Specific Hydrological Factors of the Black Sea Basin

Ukraine

460N

Azov Sea Sevastopol Gyre

Russian Federation

Crimea Gyre

Danube

450N

Romania 440N

Caucasus

Black Sea

Kaliakra

Bulgaria 0

43 N

ern West

Eas ter

G yr e

Georgia

nG

yre

0

42 N Synop Gyre Bosporus Gyre 410N 0

28 E

Sakarya Gyre 0

30 E

0

32 E

Turkey 0

34 E

Kizilirmak Gyre

360E

Batumi Gyre

380E

400E

Fig. 7.43 Modified from Stanev, E.,V., Understanding Black Sea Dynamics—An Overview of Recent Numerical Modeling [40]

The average annual situation is similar to the warm season situation, except that the cyclonic center of the western basin of the Black Sea is 10 times stronger than the center of the anticyclonic eastern basin. The records of the current speeds show their average values at the depth levels of 200, 300, and 500 m of 10, 8, and 3.2 cm/s, respectively; the minimum recorded speed is 2.8 cm/s at a depth of 750–1000 m. At a depth of 1600 m, this speed increases to the value of 3.2 cm/s due to the action of the bottom stream from the Bosphorus [39]. In 2005, the Bulgarian scientist Stanev proposed the following scheme of Black Sea currents (Fig. 7.43) [40] with a very high degree of similarity with the one presented above, but also with those presented below. After Marine.Copernicus.eu, about the RIM Current variations in the Black Sea, the conclusions are: in winter, the basic flow—the Rim Current, spanning the entire Black Sea, is stable and intense. At the end of Spring, the Rim Current weakens and begins meandered (Fig. 7.44) [41]. The US Naval Research Laboratory (NRL) developed the program Navy Coastal Ocean Model (NCOM) based on the Princeton Ocean Model with time-invariant hybrid (sigma over Z ) vertical coordinates. The Coastal Ocean Model, global version (Global NCOM), was run by the Naval Oceanographic Office (NAVOCE ANO) as the Navy’s operational global ocean-prediction system before its replacement by the Global HYCOM system in 2013 [42]. From their archive, we chose four representative maps for the four seasons of 2012–2013 (Figure 7.44a, b, c, d) [42, 43] to be able to see the similarities with the Black Sea current models presented above. After Kershaw (2015) the surface waters are driven by westward-moving winds from the Caucasus Mountains in the northeast to produce a cyclonic (anticlockwise) rim current along the continental slope that varies from weak to strong and

7.2 The Black Sea Thermohaline and Density Regimes

261

Fig. 7.44 Rim Current in the Black Sea, February 2012. (Public picture from Copernicus.eu [41])

Fig. 7.45 (a–d) Black Sea Rim Current, processed after Kershaw (2015) [44]. (Source: public pictures from https://www7320.nrlssc.navy.mil/global_ncom/glb8_3b/html/blacksea.html [42])

completes one loop around the Black Sea in only a few months. Secondly, two major anticyclonic gyres exist as permanent features, one in the east and one in the west basin. Also, anticyclonic mesoscale eddies and minor eddies develop across the

262

7 The Specific Hydrological Factors of the Black Sea Basin

Black Sea

Ukraine KHERSON ODESSA

Russian Federation Minor Eddies

13.5

Azov Sea CHORNOMORS’KE

14

SULINA

KERCH NOVOROSIYSK

Romania

YALTA

Rim Current

Minor Eddies

4

CONSTANŢA

Minor Eddies TUAPSE

Rim Current

Minor Eddies

ADLER

Bulgaria

Minor Eddies

VARNA

15 Major Eddies

BURGAS

Rim Current

ISTANBUL AIRPORT

Minor Eddies

15.5

Minor Eddies

Minor Eddies

Georgia

Major Eddies

Rim Current

Minor Eddies

Minor Eddies ZONGULDAK

Turkey

BATUMI SAMSUN TRABZON

Fig. 7.46 Black Sea rim current. (Processed after Kershaw (2015) [44])

Black Sea and are unstable, showing large changes over periods of only 3–6 months (Fig. 7.46) [44]. The observations made on current speed using radio buoys indicate a maximum average speed of approx. 40–50 cm/s, increasing to over 80–10 cm/s. Observations showed that the vertical currents are almost uniform until the water depth reaches up to 150 m. The edge of the continental shelf situated between the north-western shelf and deepwater area has an increased variability in the current direction. Variability of dynamic topography (elevation of the sea surface) can have an amplitude of 10–15 cm, and the speed at mesoscale surface currents reaches 50 cm/s [45, 46] (Fig. 7.47) [45]. The inertial currents are formed as a result of the interaction of some forces that are acting on the water masses. The total currents inertial component increases with depth; in the Black Sea, the observation period of these currents (in the opinion of Eremeev) is 16.5–17.5 h, they have a maximum life of 3–4 days and an orbital size between 3 and 5 km. The speed increases by 50% in the case of the high deep-sea modules. The wind currents depend on the winds and waves regime, therefore, after the powerful storms, their measured velocities are as follows: over 2.4 m/s in the Odesa area; over 1,9 m/s in the Yevpatoria area; 2.2 m/s in the regions of Yalta, Tuapse, and Batumi; and1.8 m/s in Constanța and Varna. The secular variation of the Black Sea level had an oscillatory character in the last hundred years with an increasing tendency due to the increase of the volume of the discharged water and the slow subsidence movements of the land. The Black Sea

7.2 The Black Sea Thermohaline and Density Regimes

263

Odessa

Sulina

Da nu be

Black Sea

Kerch Sevastopol

Novorossiysk

Kalia kra Co nst an ţa

Kerch Sevastopol Crimea

us as uc Ca

Constanţa

Tuapse

mi chu Su

re Gy

n Gy re

W

ern est

er

Bourgas

st Ea

Varna

Sinop

Poti

Kizilimak

Batumi

Sinop

Bo sph oru s

Sakarya

Batumi Zonguldak

Istanbul

Trabzon

Fig. 7.47 Circulation of an enhanced vortex in the Black Sea based on revised altimetry data analyses. (Source: modified from http://www.ims.metu.edu.tr/cv/oguz/circulation.htm (image retrieved in April 20th, 2017) [47])

level has followed the oscillations of the World Ocean levels. Following the last marine geological research, it is considered that the interglacial Riss–Wurm phase (when the sea level was higher than the present one) was followed by the following steps: the level decreases to about 100 m (the inferior value), then increases up to 0 m (e.g., the Würm inter-Ice Age), then the level decreases up to 80 m (e.g., the Würm Superior), and then increases to the present level [48]. As a result of the sea-level oscillations, the Black Sea drainage basin has changed several times (e.g., in the Inferior Quaternary, the Danube flowed in the Dacian lake, located at the western edge of the marine plain of the Danube Delta). During the Ice Ages Periods, the decreasing of the sea level was accompanied by a strong discharge of the waters in the direction of the Black Sea remaining Lake (probably, the Dacian Lake clogging happened at the end of the Post-Karangatien regression), the deposit center is represented by the high deep delta complex. The strictly deltaic environment arose after this phase and migrated inland, concomitant with the raising of the beach (at Surojnian level). The last Würm Ice Age and the decrease of the sea level (100 m) move once again the deposits in the center of the shelf edge in the high deep deltaic complex area. The geo-environment changes determined changes in the coastal zone and the position of the watercourses, the sediment intake as well as the water salinity from the freshwater to the sea (due to the sea level rising and the link with the Mediterranean Sea). The actual variation of the Black Sea level is determined by several factors with a very different regime over a period, the most important being the river intake and the

264

7 The Specific Hydrological Factors of the Black Sea Basin

unevenness caused by the wind. Other factors that influence the variation of the sea level are the climatic factors (the precipitations and the evaporations), the meteorological ones (e.g., the unevenness caused by the wind, the atmospherical pressure variation), and, to a low extent, the cosmic factors (i.e., the tidal phenomenon). The seasonal and annual variation generally found at the Black Sea level is due to the rivers’ intake. Although the level increases become significant only during the secular periods, the level variation during the storms plays an important role in modifying the base of the action of the wave. As a result of these increases, the waves’ action base changes in the direction of the approaching shore and to the extending emersion beach strip where the final wave break occurs. The Level Oscillations, the Waves, and the Sea Currents in the Western Black Sea Sector The fluctuations of the sea level in the western basin of the Black Sea follow the same scheme as the oscillations of the Black Sea level; the highest average values of the sea level are up to 18 cm (the average annual value is 5–6 cm). Also, the seiches can have a local character (e.g., at the Romanian coastline, inside the bays and port basins). Daily, they appear to have amplitudes under 5 cm, about 50% of them having amplitudes between 5–15 cm, and 1–3 times a month having amplitudes over 15 cm. At the Romanian coast the tides have a half-diurnal character, of a period of 12 h and 25 min, and the amplitude of approximately 12 cm, respectively [48]. The oscillations produced due to the water inflow-outflow, caused by the wind can be considered in the north-west sector (2 m on the shores of Crimea). On the Romanian Black Sea shore, the winds’ bumps vary depending on their general orientation and the water depth: for the shore oriented to the north-south direction, Sulina, St. George, Constanța, the winds from the north, north-east, southeast, and south are producing level increases and the winds from the south-west, west, and north-west are producing level decreases; for the shore oriented to northeast–south-west direction, Gura Portiței, the prevailing winds from the north-east, east, south-east, and south-west are producing level increases and the winds from the west, north-west, and north are producing level decreases. As regards the Romanian coast, in the shallow areas, wide beaches, Gura Portiţei, for the same wind speeds, the level increases are higher than the decreases; in the areas with high depths (Constanța), for the same wind speeds, the level decreases are higher than the respective increases. The bumps caused by the wind are extended upstream, on the Danube’s branches (i.e., on Sulina, even up to 60 km). The seiches are caused by the abrupt stop, sudden start or abrupt variation of the wind direction, the passing of cyclones or air fronts, and, in the Romanian coastline area, they could have amplitudes between a few centimeters up to 2 m. Long-term oscillations have a seasonal character, as a result of the seasonal variation of the water balance resultant. On the Romanian coast, particularly the river water intake differs, having a maximum value in May, a minimum value in October, respectively. The variations in annual average levels are directly dependent on the annual stock levels of the rivers that flow into the sea (the Danube represents 64%). A usual

7.2 The Black Sea Thermohaline and Density Regimes

265

periodicity of the annual average levels between 3 and 28 years was noticed, the small oscillations (i.e., up to 10 cm) having a periodicity of 3–5 years, the average oscillations (i.e., up to 10–20 cm) having a periodicity of 8–12 years, and the 20 cm oscillations have a frequency of 18 up to 28 years [48]. The significant annual average levels recorded on the Romanian and Bulgarian coasts of the Black Sea are Constanța in 1930, 5.0 cm, 18.2 cm in 1980, in Varna in 1895, 33.2 cm, 64.6 cm in 1928, 122.2 cm in 1980, in Burgas 72.8 cm in 1928, 124.3 cm in 1980, respectively. On the Romanian coast, the annual variation of the sea level rises from the north (10 cm at Sulina) to the south (22 cm at Constanța). Every 3–5 years, small oscillations having about 10 cm amplitudes occur, and these are integrated into wider oscillations that have the wavelengths of 18–26 years and the amplitudes of 20 cm. The tides have a period average of 12 hours and 25 minutes, and an amplitude of 10–15 cm, in Constanța. Beginning with 1933, the variation of the sea level showed high variability, the average monthly values being between 16.9 cm (February 1949), and 39.6 cm (March 1970). The annual amplitudes are between 11.0 cm (1974, the minimum value, i.e., 7.6 cm being in April, the maximum value of 18.6 cm in August, respectively) and 42.7 cm (1958, the minimum of 3.1 cm in December, respectively 39.6 cm, the maximum value in June). The multiannual monthly averages showed a strong annual cycle, having a minimum value of 6.8 cm in October and a maximum one, i.e., of 21 cm in June. The highest levels were recorded during early summer (37% of the top levels occur in June), and the lowest ones were recorded during autumn (35% of the minimum levels occur in October). The ashore waves regime depends on the regime of the sea waves, which is determined by the dominant element of the waves’ wide winds, thunder storms, and seabed topography from the western basin of the Black Sea. They are divided depending on the winds’ state direction from the sea, namely in relation to the waves front direction: the shore having the north-south direction as general orientation (Sulina – Sfântu Gheorghe, Cape Midia – Cape Kaliakra, Albena Resort – Cape Emine); the shore having as general guidance the ENE – WSW direction (Ciotica – Periteaşca); the shore with east-west direction as general orientation (Kaliakra Cape Balchik, Cape Emine – Vlas, Cape Foros – Chernomorets); the shore with NE – SW direction as general orientation (Periteasa – Vadu, Nessebar – Burgas); the shore with NNW – SSE direction as general orientation (Chernomorets – Cape Koru Burnu). The marine currents from the western basin of the Black Sea are characterized by a cyclonic direction (i.e., to east), driven by the influx of the freshwater from the north and north-west directions (Dnieper, Bug, Dniester, Danube). The off-shore current has a width of 55–75 nautical miles, and it continues to the south direction up to Bosphorus, with an average speed of 20–30 m/s, respectively [49]. The marine currents regime can be characterized as follows: from Cape Emine to the Serpent Island, the current has the general orientation to South (0.5–0.6 Kt speed) and inside the gulfs and bays (Burgas, Varna), there are circular currents, the anticyclone type (to the west direction), having the speeds of 0.1–0.3 Kt; from the Serpent Island up to Cape Tarkhankut, the currents’ regime is determined by the

266

7 The Specific Hydrological Factors of the Black Sea Basin

winds, so in case the wind currents are weak and oriented from the east, namely, from Cape Tarkhankut and to Tendre (0.3–0.5 Kt); in the west part of Karkinit Bay, there is a currents system that is moving in a clockwise direction (0.1–0.3 Nd); on the Crimean peninsula coast, the sea current is directed towards the south-west direction, i.e., to Cape Sarich. In the Romanian seaside area, in the southern part, there is a surface current (having a width of several miles) and a counter compensation bottom current to the N. The measurements taken during 30 years in Constanța show the following characteristics of the sea currents in this area: the southward currents represent 36.6%, to the SW–SSE represent 60%, the northward currents represent 22.6%; during all months, the currents having the general direction towards the south had a maximum frequency (e.g., representing 43.1% in August); the currents having a northwesterly direction had the lowest frequency, i.e., representing 1.6% in April. In front of the Danube’s mouths, perpendicular freshwater currents are formed, dispersed to the sea like a fan, up to a distance of 3 km (depending on the water flow discharged into the sea) [50].

7.3

Conclusions

In the Black Sea basin, the water exchange towards and from the Black Sea is comparatively insignificant to the total volume of the water from its basin. The Black Sea water level is subject to periodical and non-periodical vertical oscillations. The volume fluctuations are produced due to the changes occurring in the hydrological balance. The Black Sea basin and the sea itself form a single unified natural system. The rivers form a link between the landmass and the sea, supplying the marine reservoir with water discharge and output from erosion and denudation. Under natural conditions, the discharge would have been more than 381 km3. In addition to the surface discharge, at least 17 km3 of freshwater reaches the Black Sea from underground sources. Precipitation contributes another 238 km3. Thus the annual volume of freshwater entering the Black Sea (river water plus precipitation plus underground sources) is on average 603 km3. Under natural conditions, without human interference, this figure would be 636 km3. The Black Sea area gains annually 93,000 calories per square centimeter. The significant thermic variations occur only in the surface layers of the Black Sea, while in most of the water volume, there is obvious thermic inertia. In the coastal areas, the convective miscellany occurs up to the depth of 60–80 m; during the summer season, this layer is thinner and the temperature’s drop occurs at the depth of 20 m; during the winter, the surface temperature drops to 6–7  C, to 8–9  C in the southwest, and 2–3  C and even 0.6  C in the northern part. During the summer season, the surface temperature rises to 24–25  C in the east and the south. The sea surface emperature multiannual average values on the Black Sea coast for the four seasons are of 7.36  C in February, 16.34  C in May, 25.72  C in August, and 14.48  C in November.

7.3 Conclusions

267

The ice occurs in the north-western part of the Black Sea, near the shore, and the frequency of days with ice has an average of 80 days/year at the mouth of the Dnieper, in Odesa Bay from 40 to 100 days/year during the cold winters (not during mild winters), and in the Kerch Strait area 40–80 days/year. The salinity regime of the Black Sea is a brachisk one, presents lower values of salinity than 24‰ calculated on the entire mass of water, with very low values in the front of the rivers’ mouths from the north-western sector, respectively. The surface layer of the seawater has a salinity medium value of 18‰, the depth layer salinity is over 24‰, respectively. In summer, the salinity is 15–17‰ (from 6 to 7‰ in the rivers’ mouth area from the north-western part of the Black Sea basin to 19‰ and even 23‰ in the open sea areas) and in the winter season, the salinity is lower by 0.5–0.6‰ towards the values recorded in the summer season due to the lower intake of freshwater during this time of the year. As a result of the lower salinity, the density of the Black Sea waters has low-value levels, i.e., generally below 1.0180. Up to the depths of 50–70 m, the density of the seawater depends on the temperature variations, and at depths higher than 70 m, it only depends on salinity because, as it was noted above, the temperature variations are not significant for the middle and deep water layers. The water density values vary with depth: up to 70–100 m depth, the water density is between 1.0144–1.0147, over 100–125 m depth, 1.0115–1.0157, 1.0171–1.01725 at 1000 m depth, and 1,01725–1,01740 at 2000 m depth, respectively. The Black Sea is individualized by the regular level oscillations, with a maximum value during the summer season and a minimum one in the cold season of the year. The level increases gradually starting with December to a maximum in July; then it gradually decreases to the minimum in November. The small duration oscillations of the sea level are determined only by the winds, seiches, and tides. Because of the air friction at the sea surface, the winds in the Black Sea put in motion the water layer up to a depth of 50 m, having, as a result, the forming of the marine drift currents. The winds which blow from the sea are producing the water level rising at the coast and conversely, blowing from the land, they produce the water level decrease at the coast. The seiches periods in the Black Sea vary from a few minutes to 13 h, respectively the amplitude from a few centimeters to 2 m (in exceptional cases). In the Black Sea, the tide has insignificant values for navigation, i.e., of maximum of 10 cm. The Black Sea’s level is of relative growth, by 0.1–12.2 mm/year. The water level fluctuations depend on the winds’ speed and direction, the shores’ shape, and nature, the sea’s bottom topography, respectively the following: in the mountainous shores, the increase is 0.2–0.3m towards the waters’ “0” level; in the Crimean Peninsula it is between 0.4–0.9, and at the Romanian shore is 0.5–0.7m. The wind waves in the western basin of the Black Sea, the height of these waves is of 6–8 m, with a maximum value of 14 m; ashore, the value ranges from 4.3 m— Odesa value to 5.1 m—Tendre, 5.7 m—Sevastopol, 6 m—Constanța, and 8 m—on the mountainous shores; the waves energy varies depending on the area.

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7 The Specific Hydrological Factors of the Black Sea Basin

The mean rate of the sea level rise has been estimated as 2.5  0.5 mm/year over the entire Black Sea by using the gridded satellite altimetry data In the Black Sea, the current regime is specific to the currents’ regime from an isolated body of water; this is determined by the winds’ regime, the river water intake, the water density variation, and the seabed topography. Shortly, the currents from the Black Sea basin can be characterized as follows: in the cold season, in the entire basin, a cyclonic system with two centers, respectively eastern and western, and with two secondary anticyclone centers, i.e. in the north-western respectively south-eastern parts. The observations made on current speed using radio buoys indicate a maximum average speed of approx. 40–50 cm/s, increasing to over 80–10 cm/s. Observations have shown that the vertical currents are almost uniform until the water depth reaches up to 150 m. The edge of the continental shelf situated between the northwestern shelf and deepwater area has an increased variability in the current direction. Variability of dynamic topography (elevation of the sea surface) can have an amplitude of 10–15 cm, and the speed at mesoscale surface currents reaches 50 cm/s. The secular variation of the Black Sea level had an oscillatory character in the last hundred years with an increasing tendency due to the increase of the volume of the discharged water and the slow subsidence movements of the land. The Black Sea level has followed the oscillations of the World Ocean levels. Following the last marine geological research, it is considered that the interglacial Riss–Wurm phase (when the sea level was higher than the present one) was followed by the following steps: the level decreases to about 100 m (the inferior value), then increases up to 0 m (e.g., the Würm inter-Ice Age);,then the level decreases up to 80 m (e.g., the Würm Superior), and then increases to the present level.

References 1. ***Marea Neagră în zona litoralului românesc, Monografie hidrologică, The Black Sea in the Romanian seaside area, INMH, Bucureşti, (in Romanian), 1973 2. Zaitsev Y, Mamaev V (1997) Marine biological diversity in the Black Sea, a study of change and decline, GEF Black Sea Environmental Programme. UN Publications, New York 3. Jaoshivili S (2002) The rivers of the Black Sea. European Environmental Agency, Technical Report No. 71. https://www.eea.europa.eu/publications/technical_report_2002_71 4. Romanou A et al (2012) Evaporation-precipitation variability over the Mediterranean and the Black Seas from satellite and reanalysis estimates. J Clim 23(19):5268–5287. https://www. researchgate.net/publication/249611810_Evaporation-Precipitation_Variability_over_the_Med iterranean_and_the_Black_Seas_from_Satellite_and_Reanalysis_Estimates. Accessed 14 June 2020 5. Efimov V et al (2012) Estimation of water balance components in the Black Sea. Russ Meteorol Hydrol 37(11–12). https://www.researchgate.net/publication/257915095_Estimation_of_ water_balance_components_in_the_Black_Sea. Accessed 13 June 2020 6. Zavialov I (2020) Water exchange between the Sea of Azov and the Black Sea through the Kerch Strait. Ocean Sci 16(1):15–30. https://www.researchgate.net/publication/338433691

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Water_exchangebetweenthe_Sea_of_Azov_and_the_Black_Sea_through_the_Kerch_Strait. Accessed 14 June 2020 7. Shuisky YD (1993) The general characteristic of the Black Sea coasts, Coastlines of the Black Sea. American Society of Civil Engineers, New York 8. Şelariu O (1976) Structure termosaline des eaux de la Mer Noire. Rev Roum Geol Geophys Geogr. T20, Bucureşti 9. ***GLOBE Project. Influenta modificarilor geo-climatice globale si regionale asupra dezvoltarii durabile in Dobrogea-GLOBE (Influence of global and regional geo-climatic changes over the sustainable development in Dobrogea-GLOBE). Programul Parteneriate in Domeniile Prioritare 2007 (Partnerships in Priority Domains 2007 Program); 2007–2010 10. Miladinova S et al (2017) Black Sea thermohaline properties: long-term trends and variations. J Geophys Res Oceans. Accessed 7 Aug 2020 11. Sakalli A, Başusta N (2018) Sea surface temperature change in the Black Sea under climate change: a simulation of the sea surface temperature up to 2100. https://rmets.onlinelibrary. wiley.com/doi/epdf/10.1002/joc.5688. Accessed 7 Aug 2020 12. ***https://seatemperature.info/black-sea-water-temperature.html. Accessed 5 Aug 2020 13. ***https://ec.europa.eu/jrc/en/news/black-sea-water-temperatures-may-buck-global-trend. Accessed 11 Aug 2020 14. ***http://dvs.net.ru/mp/data/201911bs_sst.shtml. Accessed 11 Aug 2020 15. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24, 3rd edn. UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2010 16. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24, 4th edn. UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2013 17. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24, 5th edn. UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2017 18. ***Admiralty Sailing Directions Black Sea and Sea of Azov Pilot NP 24, 6th edn. UK Hydrographic Office, Taunton, Somerset, United Kingdom, 2019 19. ***Romanian National Meteorology Authority (ANM) Hydro-meteorological database, Constanța 1961–2019 20. Şerpoianu G, Nae I (1982) Observations saisonières sur le régime thermique des eaux marines sur le plateau continental roumain de la Mer Noire. Cercetări marine, Recherches marines 15, Constanța 21. Şerpoianu G (1980) Observations sur le phenomene d’upwelling au littoral roumain de la Mer Noire. Cercetări marine, Marine Research 13, Constanța 22. Şelariu O (1970) Some remarks on the hali-terrnal regime of the marine waters along the Romanian littoral area. Rev Roum Geol Geophys Geogr I 14. Bucharest 23. Mihailov et al (2016) Longterm variability of the water mass structure on the Romanian Black Sea shelf. Romanian Rep Phys 68(1) 24. Kosyan R, Magoon OT (1993) Man of the Black Sea Coast. In: Kosyan R (ed) Coastlines of the Black Sea. American Society of Civil Engineers, New York 25. Chiotoroiu B (1997) Climate change at the end of the second millennium (Variaţiile climei la sfârşitul mileniului II). Ed. Leda, Constanța 26. ***Romanian Black Sea Pilot. Mangalia, (in Romanian), 1991 27. Boguslavsky I et al (1998) Variation of the Black Sea level. Phys Oceanogr 9(3). https://www. researchgate.net/publication/243614773_Variations_of_the_Black_Sea_level 28. Goriacikin I, Ivanov VA (2009) Black Sea level: past, present, future. https://www.geoecomar. ro/website/publicatii/Nr.15-2009/19_bondar_BT.pdf 29. Avşar NB et al (2015) Investigation of sea level change along the Black Sea Coast from Tide Gauge and Satellite Altimetry. Int Arch Photogram Remote Sens Spatial Inf Sci XL-1/W5. International Conference on Sensors & Models in Remote Sensing & Photogrammetry, 23–25, Kish Island, Iran

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30. Avşar NB et al (2018) Recent sea-level changes in the Black Sea from satellite gravity and altimeter measurements. Int Arch Photogram Remote Sens Spatial Inf Sci XLII-3/W4. GeoInformation For Disaster Management (Gi4DM), 18–21 March 2018, Istanbul, Turkey 31. Avşar NB, Kutoglu ŞH (2020) Recent sea level change in the Black Sea from satellite altimetry and Tide Gauge observations. Int J Geo-Inf Special Issue GI Dis Manage 32. Legeais J-F et al (2018) An improved and homogeneous altimeter sea-level record from the ESA climate change initiative. Earth Syst Sci Data 10 33. Ginzburg AI et al (2011) Satellite altimetry applications in the Black Sea. In: Vignudelli S, Kostianoy AG, Cipollini P, Benveniste J (eds) Coastal Altimetry. Springer, Berlin/Heidelberg, Germany 34. Șelariu O (1997) Elements of meteorology and marine hydrology (Elemente de meteorologie şi hidrologie maritimă). Ed. Tipofin, Constanța 35. ***The Maritime Hydrographic Directorate – Database, 2000 – 2018 36. Arkhipkin Y et al (2014) Wind waves in the Black Sea: results of a hindcast study. Nat Hazards Earth Syst Sci 14. https://www.researchgate.net/publication/307704393_Wind_waves_in_the_ Black_Searesults_of_a_hindcast_study 37. Rusu L et al (2018) A joint evaluation of wave and wind energy resources in the Black Sea based on 20-year hindcast information. Energy Explor Exploit 36(2) 38. Divinsky BV et al (2020) Extreme wind waves in the Black Sea. Oceanologia 62:23–30. www. journals.elsevier.com/oceanologia 39. Eremeev V (1993) Contemporary state of the hydrophisical investigations of the Black Sea. Black Sea Research Country Profile (Level II), 3, UNESCO, IOC, Paris 40. Stanev EV (2005) Understanding Black Sea dynamics – an overview of recent numerical modeling. Oceanography 18(2) 41. ***https://marine.copernicus.eu/rim-current-variations-in-the-black-sea/. Accessed 9 Aug 2020 42. ***https://cordc.ucsd.edu/projects/models/ncom/. Accessed 8 Aug 2020 43. ***https://www7320.nrlssc.navy.mil/global_ncom/glb8_3b/html/blacksea.html. Accessed 8 Aug 2020 44. Kershaw S (2015) Modern Black Sea oceanography applied to the end-Permian extinction event. J Palaeogeogr 4(1). https://www.sciencedirect.com/science/article/pii/S209538361 5300092. Accessed 9 Aug 2020 45. Oguz T, Beşiktepe S (1999) Observations on the rim current structure, CIW formation and transport in the Western Black Sea. Deep-Sea Res I:46 46. Boşneagu R et al (2018) Simulation on marine currents at midia cape - Constanţa area using computational fluid dynamics (CFD) method. Thermal Sci 22(2) 47. *** http://www.ims.metu.edu.tr/cv/oguz/circulation.htm. Image retrieved in April 20, 2017 48. Şelariu O (1972) On the Black Sea level oscillations in Constanța (Asupra oscilaţiilor de nivel al Mării Negre la Constanţa). St. Cerc. Geogr. aplic. Dobrogea, volum festiv C. Brătescu 49. Boşneagu R et al (2018) A first approach to the impact of the global and regional geo-climate changes on the sustainable development of Dobrogea region. In: Bologa AS (ed) Dobrogea at 140 years after its Union with the Romanian State. Ex Ponto Publishing House, Constanţa 50. Boşneagu R et al (2019) Hydraulics numerical simulation using computational fluid dynamics (CFD) method for the mouth of Sulina channel. J Environ Protect Ecol 20(4)

Chapter 8

The Influence of the Hydrological Factors on Navigation and Seaborne Trade on the Black Sea

Abstract The Black Sea level variation is generally due to the input of the river runoff, the inflow-outflow of the waters, caused by the wind, and its values vary from a few centimeters up to a maximum 2 m (in certain limited areas). The volume fluctuations are of a seasonal type, annual, and multiannual oscillations, respectively, and the deformation ones are the seiches, the unevenness being caused by the winds and the tides. The influence of the freshwater input represents the characteristic of the volume oscillations, and the level ones are the level variation frequency, i.e., having the minimum value during the cold season, and the maximum value during the warm season, respectively. The bumps occur along the coastlines, and regular winds cause them, breezes or accidental winds having amplitudes not exceeding 1– 2 m, with an increased frequency in the cold season. Keywords The Black Sea · Navigation · Hydrological factors influence The influence of the hydrological currents is further on analyzed through the influence of the marine currents. In addition to the waves’ influence on navigation, and maritime transportation, they also influence the coastlines of the Black Sea.

8.1

The Influence of the Marine Currents on Navigation and Maritime Transportation on the Black Sea

For navigation, the marine currents’ knowledge has particular importance in choosing the ships’ routes (i.e., the preliminary routes). For the most favorable routes, it is necessary to know the nature of the marine currents for different sea areas, their most probable direction, and speed. The marine currents act directly on the ship by their deviation from the route, changing the speed and direction (there are special nomograms for marine currents of different speeds, for different types of ships). The information about the marine currents are contained in various nautical documents, charts, atlases, and tables; in the Pilot books, the currents’ formation, © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 R. Bosneagu, The Black Sea from Paleogeography to Modern Navigation, https://doi.org/10.1007/978-3-030-88762-9_8

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the type, the direction and speed, and their seasonal variation are analyzed from a general point of view; in the charts and atlases in use, the marine currents must be represented at a large scale (vectors represent the currents) for the information to be as accurate as possible). The tidal currents can be described directly on the navigational charts or in special tables. The existent general navigational documents do not always provide sufficient precision. For details, it is necessary to require information from the hydrographical services and from the specialized oceanographic institutions, too. The data must be analyzed critically, and also, the accumulation of new data to complete the existing ones is essential, obtained by direct measurements based on indirect calculations, but starting from other physical constants. In the navigation practice, the problem concerning the currents is solved exclusively by graphic methods that have the advantage of greater efficiency and fewer sources of errors in the determination of solutions. The graphical solution on the chart offers the advantage of the geographical image of the navigation situation, which is particularly important when navigating near the coast, or in a difficult navigation area. The direction and speed of the current are determined by the navigation’s methods, i.e., comparing the ship’s dead-reckoning position with the observed one.

8.2

The Influence of the Hydrological Factors on the Black Sea Coast

The marine shoreline dynamics involve complex morphological processes occurring in the water-shore contact area. The static and dynamic factors are contributing to the seashore configuration. The static factors are expressed by the lithological structure (especially the rocks’ hardness), the underwater slope profile, and the anthropic constructions (that are acting on the coastal currents and the sediments’ transport). The dynamic factors that determine the actual processes on the Black Sea’s coasts are the shore waves, the marine currents, and the sea-level oscillations. The waves are the main factor with a visible action in changing the coastline local configuration, i.e., by intense constructive or destructive processes. After the action of the waves, the water mass moves ashore on the beach, carrying in its movement silt in suspension. The water translation movement produces a sorting of the shore sediments, the coarsest ones being driven ashore, and the finest ones being driven to the sea, respectively. The silt dynamics, caused by the waves, generally occur up to a depth equal to half of the wave’s length. For this reason and depending on the sea’s condition, the area is wider or narrower where the alluvium is in a constant state of agitation. The coasts’ erosion caused by the waves having a high curvature is prevailing during the winter season, while the waves having a small curve achieves the sand accumulation. The currents have a secondary configuration role, and they especially occur in case of obstacles (e.g., cliffs, piers) that advance into the sea. They determine the formation of some secondary circular currents, deviated from the North-South mainstream. The streamlines slightly follow the coastline orientation, and also, under their action, the sediments transport is favored by the waves’ agitation, keeping them suspended.

8.2 The Influence of the Hydrological Factors on the Black Sea Coast

273

The level oscillations of the Black Sea that have maximum amplitude over one meter are significant because they determine the changes in the 00 attack00 line of the waves and currents to the shore. The lower levels cause the descent of the 00 attack00 line, while, in the shore area, the high levels cause the rising of this line. Usually, in the case of the latter, the waves are eroding the shore, and regarding the lower ones, the waves are bringing sediments from the nearby shallow waters. Irrespective of the morphological and lithological nature of the shoreline (i.e., a high cliff of limestone and loess with narrow beaches in the south or sand beaches in the north), on the Romanian coasts, in different sectors both erosion, as well as accumulation processes occur, which depend on the internal seawater dynamics. To eliminate any confusion, these problems are separately analyzed for Constanţa’s northern and southern sectors. In the northern area, having a low coast altitude, in some sectors, the sandy beaches become smaller every year due to the abrasion processes, while elsewhere, the waves and sea currents have a constructive action by sand depositing and beaches widening. The recent topographical surveys, compared with the older ones, show the retreat of the shoreline at a speed rate of 5–30 m per year. The erosion appears due to the perpendicular piers on the shore, too. These piers change the N-S coastline’s current direction and generate retrograde circular currents that wash the shores situated in the south, at a distance proportional to their penetration into the sea. The intense erosion from Gârla Împuțită’s mouth can be explained by an offshore penetration of over 10 km offshore, off Sulina dike that generates a strong anticyclonic current, having a negative effect on the stability of the coastline. In other parts of the northern coast, such as the Periteasca–Malcean lakes sector, although the shoreline is stable, during the storms, however, the sandbelt (100 m wide) is broken between the sea and the lakes, but it recovers quickly. Similar phenomena occur in the western part of the umbilical swamp Ciotica, where the sandbelt narrows under 60 m [1]. The general retreating process of the cliff is due to the abrasion phenomenon, but also, it is quite frequent for the cliff to retreat due to landslides and collapses, too. The marine abrasion is well represented in Agigea, i.e., in the northern part of Eforie, Costineşti, and the north of Mangalia, where the active cliffs are found. Also, there are inactive (00 dead00 ) cliffs in the southern part of Tuzla (Fig. 8.1a) [2], 2 Mai resort,

Fig. 8.1 (a) South Cape Tuzla Fig. 8.1 (b) North Cape Tuzla. (Author’s photos)

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the northern part of Vama Veche, where, at least nowadays, the marine abrasion is not felt. The “classic” waves’ erosion occurs by digging the banks, niches forming, abrasion recesses, and caves. Particularly, where the Sarmatian limestones rise by 2–3 m above the sea medium level, these forms are more precise and are maintained for a long time, unlike the sectors where the loess blanket comes in direct contact with the seawater. Such types of abrasion are met in the south of Sara, Agigea, at north and south of Eforie, Cape Tuzla, etc. The niches and recesses sizes vary from several centimeters to meters. In front of these, the rocks debris are continuously moved by the waves, hitting together the steep bank. The dams were built perpendicular to the shoreline, because of the need to increase the capacity of some beaches because of the influx of tourists. These dams, especially the T and Y-Y-shaped ones, have given satisfactory results, influencing the accumulation of silts and, thus, the widening of beaches. In addition to the coast modeling processes by erosion and marine sedimentation, in the loess cliffs, especially in the south of Constanţa and in the north of Cape Tuzla (Fig. 8.1b) [2], a modeling process by collapses and landslides has been found. They also occur in cases where the loess is at sea level and when its base is not affected by sea erosion. In the first case, when the loess base is at sea level, the wrecking process of the cliff is very active. The waterfront is not supported by the material fallen at its core, because this material consists of fine particles and it is moved off the sea by waves and currents. In the second case, the main factor of the cliff’s destruction consists of the groundwaters accrued at the loess base when the extra clay layer has not been removed. These feed ephemeral littoral small streams and also create moist areas and produce suffusion phenomena, which finally turn into landslides. A concrete example is the landslides in the lighthouse area, i.e., in the north of Tuzla. Initially, they form steps and compaction or separation ditches, followed by material sliding. The most active landslides have been observed in Sara, where, between 1961 and 1963, the cliff’s edge retreated at a speed of 5–6 m per year. Elsewhere, e.g., in the south of Eforie, the retreat is slower but still visible: the sea waves currently wash the blockhouses constructed inside the cliffs. The cliffs’ successive retreats by landslides are often generating false terraces. Also, false terraces are sometimes generated as a result of the dry loess detachments and collapses. In these cases, the deposit from the cliff’s base can have a stratification consisting of gravel deposition, as a result of the waves and the broken material from the cliff head. In conclusion, the morpho-hydrological changes in the coastal zone are occurring under the following actions: – Direct action of the waves – Input of the river sedimentary material discharged into the north-western part of the Black Sea – Anthropogenic constructions (the extension into the sea of the embankment from Sulina, Constanţa, Mangalia, and Midia ports expansion and a series of longitudinal and transversal protective hydro-technical structures) – Sea level variation

8.3 The Influence of the Waves on the Activities in the Black Sea Ports and. . .

8.3

275

The Influence of the Waves on the Activities in the Black Sea Ports and Harbors

In the seaport basins and external harbors, adjacent to these, the gravitational waves’ diffraction phenomenon can be observed; this type of phenomenon is theoretically studied by the amplitude diffusion and waves energy methods [3]. Apart from the wind waves, i.e., in front of the port (in the roadstead), low-frequency oscillations are produced on the access path from the port and the port basin, within 0.5–4 min, similarly to the seiches, but with the amplitudes of the horizontal oscillations that can reach 4 m. Such low-frequency oscillations are called horizontal waves. In case of strong horizontal waves, unexpected phenomena occur, such as breaking of the ships’ ropes, vessels and piers damaging, and vessels’ loading– unloading become impossible; therefore, they must go out of the harbor. Table 8.1 [4] presents the oscillations’ amplitudes of the moored vessel, which are admitted in the normal technological conditions of the vessels’ operation. Usually, in the port, the ship operation is carried out in three steps: – The entrance, the mooring in the dockside area – Proper operation (loading–unloading operations) – The ship unberthing and its exit from the port Referring to each stage, the waves and wind conditions may manifest negatively, but the first two stages are most affected. To analyze the economic effects due to the ships’ downtime caused by the hydrometeorological conditions, many concrete data Table 8.1 Admitted oscillation amplitudes of the moored ship, operating in the port Type of vessel Container ship Container ship General cargo General cargo General cargo General cargo Tanker

Operation procedure or the cargo Containers General merchandise in bales, containers, timber Long or heavy-duty cargo on deck, rolled metal or timber in bundles and packages; loading by round sling Great mass cargo loaded in the hold Horizontal operating with the bridge, out of the board Vacuum-pneumatic operating systems (hd – nozzle height) When the operating system is not under the Naval Register

The permissible theoretical value of the amplitude, m At the fastening system level Aη3%  0.12 At the level of the upper deck hatches Aη3%  0.20, Aζ3%  0.10 At the level of the upper deck hatches Aη3%  0.50 Aζ3%  0.30 At the operating deck level Aζ3%  0.10 Loading–unloading ramp Aζ3%  0.50 At the level of the upper deck hatches Aη3%  1.00; Aζ3%  0.60; Aζ3%  0.8hd At the deck intakes level Aη3%  1.0. . .1.5

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The Influence of the Hydrological Factors on Navigation and Seaborne Trade . . .

concerning the port’s activity and specific hydrometeorological elements are required, as well.

8.4

The Waves’ Influence on Maritime Navigation in the Black Sea

In case the sea agitation state is not taken into consideration, the wrong choice of the ship route and speed under the conditions of a rough sea or the inappropriate change of the route in stormy conditions can lead to severe consequences, such as [5]: – – – –

Damage of the ship’s hull Cargo moving on the board Overturning of the vessel Ship sinking

The big waves combined with a strong wind (especially gusts) produce a strong tossing with accentuated heelings that do not represent a real threat to the ship’s security, but it significantly increases the crew’s fatigue and reduces the attention and vigilance of the officer on watch [5]. The waves appear on the sea surface having different shapes, sizes, and a variable length. For navigation, the wind and swell waves are particularly important, defined as oscillations for a short period into the sea surface layer. The waves are characterized by: height H [m], length λ [m], period Τ [s], amplitude a [m], speed c [m/s] (Fig. 8.2), where: λ ¼ cT

ð8:1Þ

In maritime navigation, the agitation of the sea is given by the Beaufort scale. After the Royal Meteorological Society, The Beaufort Wind Force Scale, an empirical measure that relates wind speed to observed conditions at sea or on land, is as follows (Table 8.2):

T λ

Crest

a H a Trough

Fig. 8.2 Wave main characteristics

8.4 The Waves’ Influence on Maritime Navigation in the Black Sea

277

Table 8.2 The Beaufort Wind Force scale [6, 7] Wind force 0 1

Wind speed description Calm Light Air

km/h