Paper No. 13
Presentation Time: 9:00 AM-6:30 PM

WATER RESOURCE AND CLIMATE VARIABILITY IN BARBADOS RECONSTRUCTED FROM CAVE DEPOSITS


OUELLETTE Jr, Gilman Reno, Hoffman Environmental Research Institute, Department of Geography and Geology, Western Kentucky University, 1906 College Heights Blvd, 422 Environmental Science and Technology Building, Bowling Green, KY 42101 and POLK, Jason, Geography and Geology, WKU Hoffman Environmental Research Institute, Western Kentucky University, 1906 College Heights Blvd, Bowling Green, KY 42101, gilman.ouellette763@topper.wku.edu

Water resources on island nations such as Barbados are highly sensitive to changes in precipitation regimes. To manage water resources most effectively, a solid understanding of cave/climate/groundwater interactions in the region is necessary. To this end, we are developing a high-resolution reconstruction of Late Holocene (~last 2,000 years) precipitation and climate variability on the island of Barbados from multiple speleothems. Proxy climate records from speleothem stable oxygen isotope records combined with high-resolution Uranium-series dating will be used. One half of each speleothem was sampled for Uranium- series dating, in order to build a chronology of lamina deposition. The other half is being sampled for stable isotope analysis (oxygen and carbon) at a 100 micron resolution to allow for annual or better data in order to build a record of shifts in the amount of precipitation and source water characteristics that persisted when lamina were deposited. Additionally, precipitation, dripwater, and calcite are collected weekly for isotopic analysis to calibrate the current climate regime with calcite deposition. The speleothems samples will be analyzed using a non-destructive large chamber and regular SEM in an attempt to compare crystal growth within the lamina to the isotopic variability to determine if a relationship can be established between growth rate and isotopic variability along a growth layer. The reconstructed paleoprecipitation patterns will be analyzed using time series analysis, elucidating the role major climate influences play in modulating groundwater potential throughout the Late Holocene. This research will help in managing the karst groundwater resources of Barbados and the Eastern Caribbean in the face of future climate change scenarios.