Wednesday, 29 August 2007 - 10:10 AM
3.A.B-1
A circum-Antarctic synthesis of stable carbon isotope variability in Southern Ocean sedimentary sections: Insights from the modern ocean
Robert B. Dunbar1, David A. Mucciarone1, Luna Federici2, David Munro1, Lauren Rogers1, Matthew Long1, Eduard Costa1, Jennifer Villinski3, John Hayes4, Amy Leventer5, Eugene W. Domack6, Christina Riesselman1, Chris Moy1, Kevin Thiessen1, and Michael Lutz1. (1) Department of Geological and Environmental Sciences, Stanford University, 325 Braun Hall, Stanford, CA 94305, (2) Earth Systems Program, Stanford University, Stanford, CA 94305, (3) Department of Geological Sciences, Indiana University, Bloomington, IN 47405, (4) Woods Hole Oceanographic Institution, Woods Hole, MA 02543, (5) Geology Department, Colgate University, 13 Oak Drive, Hamilton, NY 13346, (6) Geosciences, Hamilton College, 198 College Hill Road, Clinton, NY 13323
The stable carbon isotopic composition of marine organic matter in Antarctic sediments has been proposed as a tracer of past variability in water temperature, sea ice extent, aqueous CO2 partial pressure, phytoplankton community composition, phytoplankton growth rates, and terrestrial sediment provenance. This diverse array of attributions has lead to uncertainty regarding when and how to use carbon isotopic data from Antarctic sedimentary organic matter in studies of past environmental change. Since 1983, we have amassed a large data set on carbon isotopic variations in Antarctic sedimentary organic matter, suspended particulate organic matter, dissolved CO2 13C/12C, sea ice organic matter, and sinking particulate matter 13C/12C. The study areas include the Ross Sea , the west coast of the Antarctic Peninsula, the Drake Passage, and about 1/3 of the east Antarctic continental margin. In this paper we summarize the major findings of a new multi-site synthesis of the data set.