Deglacial History of the West Antarctic Ice Sheet
I spent December 2012 and January 2013 in the Dry Valleys collecting glacial erratic boulders on the small percentage of Antarctica that is not covered by ice. In this case, these boulders were deposited by the Ross Ice Sheet during the Last Glacial Maximum. The goal of the project was the timing of the last deglaciation of the West Antarctic Ice Sheet from surface exposure dating methods. This involves measuring the amount of in-situ produced Beryllium-10 from interaction of quartz with cosmogenic rays. We can use the measure of this Beryllium-10 concentration to understand when the boulder was first exposed from underneath the ice, creating a deglacial history of the region.
Results of this work establish the timing of the last deglaciation of the Ross Sea Sector of the West Antarctic Ice Sheet (WAIS), addressing the question of whether grounded ice in the Ross Embayment deglaciated entirely in the Holocene or earlier.