EAGER: Deglacial Chronology of Bermuda Rise

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

This award uses funds, under the auspices of the EArly-concept Grants for Exploratory Research (EAGER) program, for a project aimed at examining the causes and significance of perplexing inconsistencies in radiocarbon dates coming from 20,000 year old deep water sediments at the northeast Bermuda Rise. The deep, northeast Bermuda Rise is a classical location for study of climate over the last glacial cycle because of its high deposition rates and good preservation of foraminifera. Since it is also contains one of the deepest records of climate change and Bermuda Rise cores have been studied for over 30 years, it has become a standard reference section for climate history. Hence, getting the radiocarbon dating right is critical to calibrating time in this region and, perhaps, elsewhere if the inconsistencies in age dating are systemic and not simply local. The research activities fit well into the potentially transformative, high risk, and exploratory nature of the EAGER programs because it is hypothesized that results from this project will show that sediments on the seafloor can be "unmixed" by dating every sample. If this hypothesis is rejected, the resulting chronology will nevertheless be an improvement on the present situation, where important results are waiting for an improved age model before they can be published. If the hypothesis is accepted, however, the new chronology could inspire new research on this and other locations in the western North Atlantic. The cores from the Bermuda Rise targeted for this project would be a valuable resource for future researchers as they will have internally consistent stratigraphies and chronologies and future proxies for ocean and climate change will be linked in a common temporal and sedimentological framework.