Caribbean hydrological variability during the Holocene as reconstructed from crater lakes on the island of Grenada |
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| Authors: | Sherilyn C Fritz Svante Björck Catherine A Rigsby Paul A Baker Amy Calder‐Church Daniel J Conley |
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| Institution: | 1. Department of Earth and Atmospheric Sciences and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA;2. Department of Earth and Ecosystem Sciences, Division of Geology, Lund University, Lund, Sweden;3. Department of Geological Sciences, East Carolina University, Greenville, North Carolina, USA;4. Division of Earth and Ocean Sciences and Nicholas School of the Environment, Duke University, Durham, North Carolina, USA |
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| Abstract: | Contemporary precipitation patterns in the Caribbean region are spatially variable, and the small number of Holocene paleoclimatic records may not adequately capture patterns of variation in the past. The hydrological history of Grenada was inferred from paleolimnological analyses of sediment cores from two crater lakes on the island. The basins were formed by volcanic activity some time during the Last Termination, but were dry between ca. 13 000 and ca. 7200 cal. a BP. After filling, the lakes were initially very shallow, and sedimentation was interrupted by a hiatus ca. 6300–5500 cal. a BP, followed by deposition of a thick tephra in both sites. After 5500 cal. a BP, lake level shows considerable multi‐centennial variability, superimposed upon a long‐term trend of generally higher lake level after 3200 cal. a BP. The pattern of lake‐level variation in Grenada shows some similarity with other Caribbean paleoclimatic records in terms of the timing of transitions, but differs from several classic studies in the sign of inferred precipitation change. The differences among records may reflect spatially variable precipitation patterns in the past in response to the position of the Intertropical Convergence Zone and to sea surface temperature influences on the trade winds and Caribbean low‐level jet. Copyright © 2011 John Wiley & Sons, Ltd. |
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| Keywords: | paleoclimate Caribbean diatoms lake level tephra |
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