Collaborative Research: An Ultra-High Resolution Holocene Climate Record from a Varved Sediment Sequence from the Adelie Coast, Antarctica (IODP Exp 318)

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A key region for analysis of long- and short-term behavior of the East Antarctic Ice Sheet (EAIS) is the eastern sector of the Wilkes Land margin, located at the seaward termination of the largest subglacial basin in East Antarctica, the Wilkes subglacial basin. The Wilkes subglacial basin may in fact respond to climate variability in a fashion similar to the West Antarctic Ice Sheet. Additionally, a significant portion of all Antarctic Bottom Water may originate from this part of the Antarctic coast, making this region a key player in oceanic circulation patterns. The Integrated Ocean Drilling Program Expedition 318 to Wilkes Land recently obtained nearly 3,000 meters of sedimentary cores. Drill site U1357, obtained a unique ultra-high accumulation rate sedimentary sequence from the Adelie Basin that extends from the latest glacial interval through the Holocene. These seasonally laminated deposits constitute one of the world's most expanded archives of environmental change during the Holocene. The sediments contain a near annual-resolution record of when and how the ice sheet margin retreated from the shelf ~12,000 kyr B.P. They also contain a record of past changes in water temperature, water mass reservoir age, stratification, productivity, sea ice extent, and possibly bottom water production throughout the Holocene. In this collaborative proposal, the P.I.'s request funding for morphometric, stable isotopic, and geochemical analyses of foraminifera recovered from the sediment column. These will be used to produce the first high-resolution (sub-decadal to decadal) foraminiferal isotopic and chemical climate time series from the Antarctic margin. Intellectual Merit - The results from this project will provide, for the first time, the requisite data at subdecadal to decadal resolution to address a number of questions related to oceanographic and climatic changes that occurred on and around Antarctica during the Holocene, including: 1) How does the style and timing of deglaciation along the East Antarctic Margin compare with other parts of the Antarctic Margin? 2) What were the responses of the East Antarctic Margin glacial system to deglaciation as well as global and regional Holocene climate fluctuations? 3) How did oceanic circulation and bottom water production vary during the Holocene? As part of our post-expedition educational outreach, we will organize two additional interactive webcasts targeting science museums and secondary schools during the course of this research. At Stanford, we will continue to disseminate the results of this work to secondary schools via a funded NASA project wherein he is meeting regularly with science teachers from around the SF Bay Area. Additionally, we are engaging up to 8 undergraduate students at Queens College and Stanford University in the project as interns and will guide them through the process of envisioning