216 82 41MB
English Pages 110 [113] Year 2012
Philip P. Betancourt
The Dams and Water Management Systems of Minoan Pseira Excavations at the Bronze Age seaport on Pseira Island uncovered the remains of sophisticated water retention systems that included the addition of retaining walls to prevent erosion, massive dams with associated reservoirs, and small check-dams to ravines that reached over one hun-
The Dams and Water Management Systems of Minoan Pseira
dred meters in length in order to control water runoff and make it available for human use. that the ancient inhabitants of the island went to great lengths to control water runoff and make it available for human use. Despite the application of traditional archaeological survey methods, the full extent of the water management systems was not understood fully as the island’s rugged topography prevented intensive and thorough survey of many places. Recent acquisition of a differential Global Positioning System (dGPS) unit provided excavators with the opportunity to take a fresh look at the evidence for water management on the island. The results of this study contribute substantial amounts of new information on the little known subject of Minoan water conservation and control.
The Dams and Water Management Systems of Minoan Pseira
Agriculture was one of the cornerstones of the Bronze Age Cretan economy, and it is no surprise
INSTAP Academic Press
INSTAP Academic Press
Philip P. Betancourt
INSTAP Academic Press
The Dams and Water Management Systems of Minoan Pseira
The Dams and Water Management Systems of Minoan Pseira
Philip P. Betancourt with an Appendix by Floyd W. McCoy
Published by INSTAP Academic Press Philadelphia, Pennsylvania 2012
Design and Production INSTAP Academic Press, Philadelphia, PA
Printing and Binding Thomson-Shore, Inc., Dexter, MI
Library of Congress Cataloging-in-Publication Data Betancourt, Philip P., 1936The dams and water management systems of Minoan Pseira / Philip P. Betancourt. p. cm. Includes bibliographical references and index. ISBN 978-1-931534-66-6 (pbk. : alk. paper) 1. Pseira (Extinct city) 2. Pseira Island (Greece)—Antiquities. 3. Excavations (Archaeology)—Greece—Pseria Island. 4. Bronze age—Greece—Pseria Island. 5. Water-supply engineering—Greece—Pseria Island. 6. Irrigation engineering—Greece— Pseria Island. 7. Architecture, Minoan—Greece—Pseira Island. I. Title. DF221.C8B563 2012 333.91’2093918—dc23 2012003197
Back cover photo courtesy of Jerolyn E. Morrison.
Copyright © 2012 INSTAP Academic Press Philadelphia, Pennsylvania All rights reserved Printed in the United States of America
Dedicated to Richard Hope Simpson
Table of Contents
List of Figures.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Acknowledgments.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. The Pseiran Agricultural Crisis in the Middle of the Second Millennium B.C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. The Pseiran Water Management Systems. . . . . . . . . . . . . . . . . . . . . 23 4. Comments and Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Appendix: Geological Setting for the Dams of Pseira, Floyd W. McCoy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
vii
List of Figures
Figure 1. Figure 2. Figure 3. Figure 4.
Figure 5.
Figure 6.
Figure 7. Figure 8.
Figure 9.
Map of Crete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi Chronology chart for the Aegean Bronze Age. . . . . . . . . . 2 Pseira as seen from Crete, looking north. . . . . . . . . . . . . . 3 A red limestone lamp (HM 1106) and a triton shell with the interior coils removed to make it into a cup (HM unnumbered) found in Building AB. . . . . . . . . . . . . 4 Basket-shaped vase decorated with double axes (HM 5407), deliberately made with a hole in the base, found in Building BQ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Bull-shaped vessel with a hole in the back of the neck for filling and a smaller hole at the mouth for pouring (INSTAP-SCEC no. PS 3643). . . . . . . . . . . . . . . 5 Ridge Road in the settlement on Pseira, looking south, with Building AC (the shrine) on the left. . . . . . . . . . . . . 6 Reconstruction of the upper part of one of the women in the relief fresco in the Pseiran shrine, by Maria C. Shaw (rendering by Giuliana Bianco). . . . . . . . . . . . . . 7 Marine Style vases from Pseira: a) bridge-spouted jug decorated with argonauts (HM 5381) found in Building BE; b) ovoid rhyton decorated with dolphins (HM 5408) found in Building BQ. . . . . . . . . . . . . . . . . . . 7
ix
Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33.
x
Aerial photograph of Pseira showing the location of several features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Plan of the settlement at Pseira at the height of its size in LM IB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Middle Minoan and Late Minoan terraces, groups of terraces, and other mapped locations on Pseira Island. . 18 Water management system associated with Dam M9. . . 26 Dam M9 looking upstream in 2010. . . . . . . . . . . . . . . . 27 State plan of Dam M9 showing elevations above sea level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Tumble of boulders downstream from Dam M9 in 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Sections through the ravine of Dune Creek. . . . . . . . . . . 30 Dam M9 before excavation in 1990. . . . . . . . . . . . . . . . . 31 Dam M9 after excavation in 1990. . . . . . . . . . . . . . . . . . 31 Detail of Figure 19 showing the excavated part of the structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Dam M9 as seen from the uphill side in 1990. . . . . . . . . 32 The flat capping stones in situ at the southern end of Dam M9 in 1990, looking northeast. . . . . . . . . . . . . . . . 33 Cross wall at the northeastern end of Dam M9 in 2010. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 The water management system associated with Dam M29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Sections across Middle Creek. . . . . . . . . . . . . . . . . . . . . 38 State plan for Dam M29 showing the elevations above sea level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Surviving part of Dam M29, looking northeast in 1990. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Detail of the surviving parts of Dam M29 near the center of the structure. . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Dam M29 looking southwest in 1989, showing west part of dam with remaining core. . . . . . . . . . . . . . . . . . . 41 Terrace wall G2 showing the front of the terrace, looking northeast, in 1990. . . . . . . . . . . . . . . . . . . . . . . . . 45 Plan of the trench location in Terrace G2. . . . . . . . . . . . 46 Section for Terrace G2. . . . . . . . . . . . . . . . . . . . . . . . . . 46 Section for Terrace Q21. . . . . . . . . . . . . . . . . . . . . . . . . 47
LIST OF FIGUR ES
Figure 34. Figure 35.
Figure 36.
Figure 37.
Figure 38. Figure 39.
The shrine building at Pseira. . . . . . . . . . . . . . . . . . . . . 50 LM IB sherds from the fill behind Dam M9 compared with similar pieces from Block AF in the Pseiran settlement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Spout from a LM IB jug from Dam M9 compared with a fragmentary LM IB jug from Block AF in the Pseiran settlement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Topographic map of Pseira with the stream courses for Site Creek, Middle Creek, and Dune Creek depicted and corresponding watershed areas. . . . . . . . . . . . . . . . . . . . 65 Longitudinal topographic profiles along the thalweg of Dune and Middle Creeks. . . . . . . . . . . . . . . . . . . . . . 66 Geologic cross-section across Dune Creek at the position of the dam at excavation site M9, illustrating the topography across the stream. . . . . . . . . . . . . . . . . . . 68
LIST OF FIGURES
xi
Preface
When the Temple University archaeological project was excavating at the Bronze Age seaport on Pseira Island and Richard Hope Simpson discovered two massive stone and soil dams that were built in the middle of the second millennium B.C., we knew we had opened a new chapter in prehistoric engineering and water management. What we did not realize at the time was that these dams were not isolated constructions in the countryside, but parts of very sophisticated water retention systems. The Pseirans added retaining walls to prevent erosion, massive dams with associated reservoirs, and small check-dams to ravines that reached over one hundred meters in length in order to control water runoff and make it available for human use. Additional examples of Minoan dams have now been recognized at Gournia, Choiromandres, and perhaps Chalinomouri (all in eastern Crete), so we know that these Bronze Age projects were well known to Minoan builders as one of the options available to them to improve their agricultural potential. The restudy of the Pseiran examples over 20 years after they were discovered results in a much better appreciation of how they were used. The opportunity to take a fresh look at the Pseiran water management system was inspired by the purchase of a differential Global Positioning System (dGPS) unit by the INSTAP Study Center for East Crete (INSTAPSCEC). The unit uses satellite links to establish points for measuring and mapping, and a trained operator can map a region in a single day in a way that would once have required weeks. The unit is especially useful in a rugged topography like the island of Pseira where in many places no
xiii
previously surveyed points are visible for measuring. We are extremely grateful that the INSTAP Study Center offers this service to archaeological projects; and the results achieved for this study contribute substantial amounts of new information on the little known subject of Minoan water conservation and control. Agriculture was one of the cornerstones of the Bronze Age Cretan economy, and the ways to improve it must have been a major concern for those who depended on it for their existence. Philip P. Betancourt 2011
xiv
PR EFAC E
Acknowledgments
The additional study that was directed to the dams on Pseira is indebted to a great many people. First, thanks are due to Richard Hope Simpson for doing such a splendid job of excavating and publishing these monuments of Minoan engineering and to my good friend and colleague Costis Davaras who collaborated with me for the excavations when the dams were discovered about 20 years ago. The clear presentation of the primary evidence by Richard was essential to our present understanding of how the dams functioned. The new work was conducted under permits issued by the Greek Ministry of Culture, and we are grateful to Vili Apostolakou, director of the 24th Ephorate of Classical and Prehistoric Antiquities, and Jack Davis, Director of the American School of Classical Studies at Athens, for arranging for the permits. The Institute for Aegean Prehistory (INSTAP) and Temple University, both located in Philadelphia, Pennsylvania, provided financial support. The new project was made possible by Thomas Brogan, director of the INSTAP Study Center for East Crete in Pacheia Ammos, Crete. Floyd McCoy is grateful to Sherry Fox and the other personnel of the Wiener Laboratory and the American School of Classical Studies at Athens for expediting his work there. Antonia Stamos and Doug Faulmann used the differential GPS to measure the dams and their setting. Computer processing was accomplished by Antonia Stamos, Susan Ferrence, and the authors. Thanks are extended to
xv
Stella Chryssoulaki, who read the manuscript and made many helpful suggestions. Yannis, Aristidis, and Maria Chalkiadakis were gracious hosts at the Tholos Beach Hotel in Kavousi, Crete, and special thanks are due to Yannis for transporting the team to the little island with speed and safety.
xvi A C K N O W L E D G M E N T S
Abbreviations
Bibliographic abbreviations follow the conventions suggested in the American Journal of Archaeology 111.1 (2007), pp. 14–34.
asl
above sea level
cm
centimeter(s)
EM
Early Minoan
d dGPS
diameter differential Global Positioning System
ET
evapo-transpiration
FN
Final Neolithic
ft
foot/feet
INSTAP-SCEC
Institute for Aegean Prehistory Study Center for East Crete, Pacheia Ammos, Crete, Greece
kg
kilogram(s)
km
kilometer(s)
lb(s)
pound(s)
LM
Late Minoan
m m asl
meter(s) meters above sea level
g GPS
gram(s) Global Positioning System
ht HM
height Archaeological Museum, Herakleion
Ppt
precipitation
I
infiltration
RO
runoff
sec
second(s)
mm
millimeter(s)
MM
Middle Minoan
xvii
Figure 1. Map of Crete.
1
Introduction
The Minoan archaeological site of Pseira makes a good test case for the examination of prehistoric water management for several reasons. It has two carefully excavated examples of Bronze Age dams and their associated corollary constructions, and the remains are reasonably well preserved. As a small island with only one main settlement, it provides information on one specific group of people and their responses to a need for better control of their environment. An island, of course, has carefully conscribed natural boundaries. Limits to a local territory that are set by topographic borders are always useful, even though in this case an obvious interrelation with nearby Crete (Fig. 1) played an important part in the community’s economic and social development. Because the challenges that made the creation of a water conservation plan necessary can also be documented, the response can be compared with the goals. Pseira was excavated in 1906 and 1907 and again in more recent times (for the early excavations, see Seager 1910; for the more recent work, see Betancourt and Davaras, eds., 1995, 1998a, 1998b, 1999, 2001, 2002, 2003, 2009; Betancourt, Davaras, and Hope Simpson, eds., 2004, 2005). These excavations provide a good base of information about the community that lived on the island during the third and second millennia B.C. It is the results of these excavations that allow us to assess the conditions that must have
1
Traditional High Chronology Chronology Dates B.C. Dates B.C.
Crete
Greek Peninsula
EM I
EH I
Aegean Islands
Grotta-Pelos Group Kampos Group Before 3000 to about 2000
EM IIA
Keros-Syros Group EH II
EM IIB EM III
Kastri Group EH III
Phylakopi I Group
MH
MC
MM IA MM IB MM IIA 2000–1625
2000–1725 MM IIB MM IIIA MM IIIB
1625 –1525
1725–1625
LM IA
LH I
LC IA
1525–1450
1625–1500
LM IB
LH IIA
LC IB
1450–1425
1500–1425
LM II
LH IIB
LC II
1425–1300
1425–1300
LM IIIA
LH IIIA
LC IIIA
1300–1200
1300–1200
LM IIIB
LH IIIB
LC IIIB
1200–1125
1200–1125
LM IIIC
LH IIIC
LC IIIC
Figure 2. Chronology chart for the Aegean Bronze Age.
been behind the desire to improve water conservation as well as the ways that the needs were implemented. Pseira’s inhabitants shared the culture of Minoan Crete (Fig. 1). For ease in description, the Bronze Age in Crete is divided into Early Minoan (EM), Middle Minoan (MM), and Late Minoan (LM), with smaller sub-periods for individual phases (see the chronological table in Fig. 2). The large island of Crete at the south of the Aegean was settled well before the Bronze Age, and it was already well populated by the Early Bronze Age (Early Minoan) during the third millennium B.C. By Middle Minoan times its people had large population centers with splendid palaces as well as towns, small villages, 2
C HAPTER 1
Figure 3. Pseira as seen from Crete, looking north, with Senta German (photo by P. Betancourt).
and isolated farmsteads. The largest and most influential palace was at Knossos (Evans 1921–1935). A large community lived on Pseira, even though the island had a limited amount of agricultural land for exploitation. The settlement of the islet provides ample proof of the large size of the Minoan population and its need for farmland. Pseira, located in the Gulf of Mirabello in northeastern Crete (Fig. 3), was inhabited from the Final Neolithic (FN) period (before 3000 B.C.) until just before the end of the Bronze Age, about 1200 B.C. Its landmass is about 1.75 square kilometers, with steep cliffs along the northwestern side and a lower coastline at the north and southeast. This situation was very beneficial for maritime activities. Because the prevailing winds in this part of the Mediterranean come mostly from the north or the northwest during the main sailing season, the southeastern coast of Pseira was well protected. A substantial town was built on both sides of a fine harbor facing southeast, toward Crete, and the settlement was a prosperous and wealthy community until the time when general destructions across Crete at the end of the first stage of the Late Bronze Age (LM IB) left much of the island in ruins. These destructions, which were due to warfare (Betancourt 2009a, 161), marked an end to the tiny island’s wealthy maritime economy. The population was INTRODUCTION
3
Figure 4. A red limestone lamp (HM 1106) and a triton shell cup (HM unnumbered) found in Building AB (photo by P. Betancourt).
Figure 5. Basket-shaped vase decorated with double axes (HM 5407), deliberately made with a hole in the base, found in Building BQ. Ht. 19.5 cm (photo by P. Betancourt).
smaller after this destruction, and the island’s inhabitants never regained the affluence of earlier times. As a background to the construction of the sophisticated water management systems on the island, it is important to understand that in spite of the fact that it was situated on a tiny island, the town on Pseira was a wealthy seaport that was in close contact with the major palaces on Crete. The settlement had about 60 houses, and many of them were large and spacious. The house at the north of the town square, called the Plateia Building, had over 30 rooms; in addition to storage and living quarters, it accommodated manufacturing workshops that made stone vases, cups from triton shells by sawing and removing the interior coils, and other objects to export to other places (Floyd 1998, 201–204). Two examples of products that may have been made in the town are shown in Figure 4. The residents lived in 4
C HAPTER 1
houses that were built of stone, and most of their buildings were at least two stories high. Because the peninsula adjacent to the harbor had some steep areas, Pseiran architectural traditions included terracing, building up the ground to make level foundations, and adjusting the architecture and the pavements to accommodate the flow of water during rainstorms. Smallscale water management was not an unknown subject. As a harbor town, Pseira was an active seaport. Its situation on the southeast of the island created a sheltered haven within its harbor, and ships from many places must have stopped there. The inhabitants imported pottery and other items from locations on Crete as well as the Cycladic islands, the Dodecanese, Cyprus, and the Levant (Banou 1995). Since Pseira had no clays that were suitable for making pottery, it imported all of its ceramics, including both its humble vessels for cooking and storage and its fine display pieces. Some of the imported pottery, like the ritual vessel in the form of a basket with a hole placed in the base so liquid would flow out continuously, was as fine as anything produced in Crete at this time (Fig. 5). Both the clay and the style of painting associate the vase with the ceramic production at Knossos. The Pseirans brought raw materials to their island for their stone vase industry, and they exported the finished products, like the red stone lamp shown in Figure 4. Some of these raw materials, including a unique type of white-spotted obsidian that only occurs on the island of Gyali, situated in the southeastern Aegean, provide proof for distant mercantile contacts (Betancourt 1997). Ceremonial activities have also left evidence in the archaeological record. Bull-shaped rhyta and other exotic vessels played an important role in ceremonies (Fig. 6). The town’s shrine (Fig. 7, at left) had fresco paintings rendered on plaster that was modeled in relief before it was painted (Fig. 8).
Figure 6. Bull-shaped vessel with a hole in the back of the neck for filling and a smaller hole at the mouth for pouring (INSTAP-SCEC PS 3643). It depicts a bull covered with a net. Found in Room AF 6, Building AF North (the House of the Rhyta), fallen into the ground floor from a shrine on the second floor. (Drawing after Floyd 2009, fig. 14:AF 208.)
INTRODUCTION
5
Figure 7. Ridge Road in the settlement at Pseira, looking south, with Building AC (the shrine) on the left (photo by P. Betancourt).
The scene that survives shows women in elaborate costumes whose beautiful detail suggests that the painters came from the palace at Knossos (Shaw 1998, 72). The tiny islet of Pseira, less than 2 km from Crete, was always well integrated within Minoan culture. Like the economic system, the town’s religious symbolism associates the island’s residents with the society of nearby Crete. The container decorated with images of double axes (Fig. 5), like the two special vases with marine style designs shown in Figure 9, can be regarded as part of the Minoan symbolic repertoire (Marinatos 1993, 49–50; Müller 1997; Koehl 2006, 333–335). Pseiran social systems and ceremonial activities, like many other practices on the island, indicate that the people who lived here were in constant contact with their neighbors on Crete. The integration of Pseira within the Minoan economic and social networks is an important aspect of the island’s history. It indicates that the community’s inhabitants would not have been isolated when a challenge to their agricultural system led to a need for a serious improvement in their harvests. Expertise in engineering and water conservation would have been available either from Crete or from somewhere else in the eastern Mediterranean. The Pseirans were seafarers who were actively trading
6
C HAPTER 1
Figure 8. Reconstruction of the upper part of one of the women in the relief fresco in the shrine building, by Maria C. Shaw (rendering by Giuliana Bianco; after Shaw 1998, end papers).
Figure 9. Marine Style vases from Pseira: a) bridge-spouted jug decorated with argonauts (HM 5381) found in Building BE; b) ovoid rhyton decorated with dolphins (HM 5408) found in Building BQ. (After Betancourt 2007, 86, fig. 5.14; drawing by Halvor Bagge.)
over long distances, and they were routinely in touch with many other ports. The evidence for the source of the expert knowledge on how to address water management problems does not survive, but the historical situation indicates that it could have come from Crete or from some much more distant location.
INTRODUCTION
7
2
The Pseiran Agricultural Crisis in the Middle of the Second Millennium B.C.
The topographic location of the Pseiran dams with their associated water management systems suggests that they were developed in order to improve agriculture and animal husbandry more than to provide water for the town. The systems are situated up in the hills away from the houses, and a ravine that terminates at the town itself did not receive any dam (Fig. 10). The water source for the domestic needs has not been discovered, probably because it consisted of wells that are hidden beneath later erosion. The digging of wells began early in Cretan history (Mantelli 1992; Wilson 2007), and the practice is well known from the time of the Pseiran dams (Sackett, MacGillivray, and Driessen 2007, 1; Apostolakou 2008, fig. on p. 24; for a well or cistern at Chamaizi, see Davaras 1992, 81). The most suitable location for a well near the Pseiran settlement would have been in the ravine that is adjacent to the main part of the town. Water there would flow downhill beneath the surface, and it easily would be reached using Minoan technology. Unfortunately, the ravine is filled with waterworn stones, and no traces of where a well might be located are present on the surface. The implication from the absence of any water management system within this ravine is that the need for the new water conservation measures developed from strains on food production, not from household needs.
9
Figure 10. Aerial photograph of Pseira showing the location of several features (adapted from a Google Earth image by Antonia Stamos).
Several different types of evidence document situations that would have affected Pseiran food production. Farming and animal husbandry made a substantial contribution to Pseiran life, and they were integral components of the community’s domestic economy. Any challenge to these aspects of the island’s livelihood would need to be addressed in a serious way.
Climate Changes Within the period between 3000 B.C. and the middle of the second millennium B.C., the climate of the southern part of the Aegean gradually changed. The situation has been best documented by pollen studies. Fossil pollen has been collected by coring at several locations in Crete, including at Tersana and Limnes on the Akrotiri peninsula in northwestern Crete (Moody 1987), at Hagia Galini in the south-central part of the island (Bottema 1980), and at Lake Kournas (Bottema and Sarpaki 2003). Additional cores from elsewhere in the southern Aegean confirm the picture from these studies (for the locations of 15 cores in Greece, see the map published by Moody, Rackham, and Rapp 1990, 16, fig. 5). Palynological studies gather and record the
10
C HAPTER 2
pollen that fell in antiquity and became fossilized. Because the species of plant can be determined by the characteristics of the pollen, the results are extremely useful in climate studies. The periods are usually dated by radiocarbon samples taken at intervals within the cores. The pollen information and the various ramifications for our knowledge of the ancient environment of Crete that result from this evidence have been examined in several studies (e.g., Rackham 1990; Moody, Rackham, and Rapp 1990; 1996; Rackham and Moody 1996, 123–128; Morris 2002, 11–13; Clark 2004; Moody 2009). The conclusion in regard to climate change in Crete is very important. It is nicely summarized by Moody, Rackham, and Rapp (1990, 21), who note that, “Between the end of the Neolithic, c. 3000 B.C., and the Middle Bronze Age, c. 2000 to 1700 B.C., all the pollen diagrams studied show a marked decline in deciduous oak and in sensitive Central European tree pollen like linden and birch.” Linden and birch are good indicators for the presence of substantial rainfall because they are trees that require a wet climate. The conclusion is that the climate of southern Greece and Crete changed during the Bronze Age, and that by the middle of the second millennium B.C. it was much drier than it had been in the Early Bronze Age. This long-range change, however, may not have occurred as a gradual and progressive development, but as a series of short and disruptive episodes. A period of drought ca. 2200–2000 B.C. has also been recognized by others (Dalfes, Kukla, and Weiss 1997). Moody suggests (2009, 244) that after this period of aridity, conditions for agriculture improved between 2000/1900 B.C. and 1800/1700 B.C., with a period of cooler summers and warmer winters. This episode was followed by a “Little Ice Age” at the middle of the second millennium B.C. when several glacial advances occurred in Europe and elsewhere (Grove and Grove 2004; for the impact on Crete, see Moody 1997). The cooler period seems to have been caused by minimal sun spot activity and the dust clouds from several volcanic eruptions, including Thera (for the ash clouds, see Friedrich 2000, 67–81; McCoy 2009). Jennifer Moody has collected evidence for a “Little Ice Age” during the second millennium B.C. comparable to one experienced by this island during the Middle Ages (Moody 1997, 2000, 2009). The evidence consists of traces of violent floods that suggest a period of extreme weather conditions between the Middle Minoan and Late Minoan periods. These floods seem to have occurred in many parts of the island. Moody concludes that they will have been very disruptive. As she summarizes the situation, “It seems clear that the rhythm of agricultural life which formed PSEIR AN AGRICULTURAL CRISIS
11
the basis of Minoan civilization would have been disrupted by periodic debris flows and floods. The construction of Minoan dams, such as the ones at Pseira, make more sense within this sort of climate reconstruction” (Moody 2000, 58–59). The evidence for flooding at the beginning of the Late Bronze Age (Moody 2000, 55–58) suggests that the period may have had extreme fluctuations in rainfall, which would have seriously affected agriculture. In conclusion, the evidence indicates a long-term development toward a drier climate that was expressed in short and disruptive episodes. Pseira may have been particularly sensitive both to this long-term climate trend and to the shorter periods of fluctuations in rainfall and temperature. Its soils do not hold moisture well. The soils studies conducted by Julie Clark as a part of the Pseiran intensive surface survey thoroughly examined both the red terra rossa and the brown soils that developed over phyllite bedrock on the island (Clark 2004). The poor quality of the rocky and porous terra rossa soils has also been examined in other studies (Morris 2002, 45–59). Neither soil is very good for agriculture. The terra rossa soils do not hold moisture well, and the brown soils of Pseira contain more stones than the brown soils of nearby Crete (for example, at Chrysokamino, for which, see Betancourt 2006, 250), so that they, also, do not hold moisture in a satisfactory way. The soils of Pseira that would dry out quickly must have made the island more sensitive to arid seasons than places with better sediments, and steps would need to be taken if the farmers wished their crop yields to be similar to what they had grown to expect. P SEIRAN E VIDENCE
FROM
A RCHAEOLOGY
Modern Pseira’s climate is very different both from the situation in the Middle Minoan and the early Late Minoan periods and from the modern situation of nearby Crete. The modern contrast with the Minoan period of habitation can be traced by the different tree species in the two periods. Conditions on Pseira are not favorable for the preservation of pollen, but small pieces of wood charcoal collected from the archaeological excavations provide a good record of the trees that were present on the island between Middle Minoan and Late Minoan I. They suggest an extreme contrast with the situation in modern times. Today, the entire islet of Pseira supports less than a dozen very stunted trees. Efforts by the Greek forestry service to re-introduce several species to the island during the 1980s and 1990s were not very successful. The climate is too dry, and large plants do not grow well (for a detailed description of the modern 12
C HAPTER 2
flora of the islet with the documentation of 92 species, see Rackham and Clark 2004). Among the modern species that are found on the island are several plants that thrive only in semi-desert conditions, including the saltbush (Atriplex halimus), a low shrub that is rare on nearby Crete where the climate is distinctly wetter. Tiny bits of charcoal that mostly came from cooking fires were collected during the modern archaeological excavations and analyzed to determine the species of wood (Schoch 1995, 1998a, 1998b, 1999). A total of 395 samples were examined for wood species, which is a large enough number for a good picture of the island’s tree population during late MM and LM I. The amount of terracing on the island proves that agriculture was practiced, but the many steep areas and the ravines would have been unsuitable for crops, and (as in modern East Crete) they would have been an easy source for firewood. One cannot be certain that additional wood did not come from Crete, but the large percentage of olive in the analyses suggests that pruning local trees provided a large share of the fuel. Identified trees from deposits whose latest date is LM I include the following: Olive (Olea europaea), 190 pieces (49%) Pine (Pinus brutia), 97 pieces (25%) Oak (Quercus sp.), 59 pieces (15%) Terebinth (Pistacia sp.), 17 pieces (4%) Broadleaf, unidentified, 8 pieces (2%) Tamarisk (Tamarix sp.), 6 pieces (2%) Heath (Arbutus cf.), 5 pieces (1%) Coniferous tree (Juniperus cf.), 4 pieces (1%) Almond (Prunus dulcis), 3 pieces (