Collaborative Research: Reorganization of deepwater circulation in response to the opening of Southern Ocean passages in the middle/late Eocene (40-33 Ma)

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This awards supports an investigation of the deepwater circulation response to the opening of the Southern Ocean passages in the Eocene. The PIs will generate benthic foraminiferal stable isotope data from the middle-late Eocene in multiple ocean basins to test the hypotheses that (1) the internally stratified Cenozoic ocean structure began ~40 Ma in response to increasing dense southern component water relative to northern component water, and (2) interbasinal oxygen isotope gradients gradually increased through the late Eocene as southern ocean gateways progressively deepened, allowing the proto-Antarctic Circumpolar current to develop and strengthen. The data generated will shed light on the relationship between ocean circulation changes and the alteration of the marine carbon cycle as reflected in the carbonate compensation depth, and on the development of a better defined internal ocean structure and associated nutrient distribution as a forcing mechanism for these changes. Broader impacts include education and training of a PhD student, involvement of undergraduates in laboratory research, and outreach to local high schools via guest lectures and curriculum development.