A 2,000 YEAR PALEOCLIMATE RECONSTRUCTION FOR THE CARIBBEAN AND WESTERN ATLANTIC: IMPLICATIONS FOR HUMAN MIGRATION THROUGHOUT THE BAHAMAS

Climate and human interactions have become a focus of investigation in many contexts, time periods and cultures in recent years. Unlike other areas of the world, Caribbean and Western Atlantic paleoclimate is not well understood at temporal and spatial scales appropriate for analyzing human/climate interaction. Climate, particularly related to moisture regimes and storminess, is heterogeneous spatially today and has varied through time in the Caribbean and Western Atlantic. To better understand the nuanced climate record of the Caribbean and Western Atlantic, we present a paleoclimate data synthesis, including new sediment records from the central Bahamas islands of San Salvador and Eleuthera in the context of temporal uncertainty in published records. We present a synthesis of a paleoclimate proxies collected from diverse sedimentary environments in the Caribbean, Western Atlantic, Mesoamerica and Northern South America. Stable isotopes (ostracode and gastropod δ18O), grain size, percent sand, elemental concentration (Ti, Fe), Mg/Ca ratios, Sr/Ca ratios, a biological transfer function, and red color intensity from lake and marine sediment cores and carbonate δ18O from speleothems provide high resolution, multi-proxy evidence of climate change. These proxies capture signals at varying sensitivities and resolutions. Important global climate events, like the Medieval Climate Optimum, are represented in the paleoclimate records, but do not occur exactly at the same time or for the same duration throughout the study region. Additionally, major shifts in hurricane activity over the Caribbean and Western Atlantic appear to be coincident with human migration patterns. The heterogeneity of climate and hurricane activity in this relatively small study area is caused by the complex interaction of atmospheric and oceanic phenomena, such as the North Atlantic Oscillation, El Nino Southern Oscillation and the latitudinal migration of the Intertropical Convergence Zone. Our results have important implications for understanding the timing of human migration throughout the Bahamas Archipelago amidst changing climate and hurricane frequency in the Caribbean and Western Atlantic.