Radiocarbon Ventilation Ages and Climate in the Northern Subtropical Atlantic

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This proposal seeks funds to conduct paleo-ocean and paleoclimate studies of deep ocean sediments from high deposition rate sites in the western subtropical North Atlantic. In the first year, research will be conducted on existing samples from Laurentian Fan and new samples will be collected during a three week surveying and coring cruise to locations between Newfoundland and the Mid Atlantic Ridge (MAR). Each location will be sampled with a multicorer, a gravity corer, and a large diameter long piston corer. The underlying theme of this research is to link radiocarbon ventilation ages in the deep ocean, as measured by paired 14C analysis of benthic and planktonic foraminifera, with surface ocean conditions on different spatial and temporal scales across the last 20,000 years. The primary scientific emphasis will be on developing a time series of ocean ventilation for the past several millennia, including the Little Ice Age, and targeting extreme climate events of the past 20,000 years since the end of the ice age. At present, there are insufficient published radiocarbon data to confirm whether or not significant ocean ventilations changes were associated with climate shifts in recent millennia. If the expected results show continuous, systematic changes in ocean ventilation in the recent past, then these results will provide an important boundary condition for understanding how global change and deep ocean circulation are linked. This research will have broad impact through taking teachers to sea and using web-based media to communicate with them and students as the project develops.