This award supports a series of field measurements that will improve our understanding of the East Antarctic ice sheet. The objectives of this project are to take advantage of the overland traverse logistics framework provided by US ITASE and to collaborate with other US ITASE investigators to calculate rates of ice sheet thickness change (mass balance) on domes, along elevation contours and along flow lines in East Antarctica using precise global positioning system methods. In addition, the variability (both spatial and temporal) in snow accumulation rates will be assessed using shallow ice cores and ground-penetrating radar profiling, and will provide the capability to deduce true past climate variation in accumulation rates in ~200-year long ice core records by measuring ice motion and upglacier gradients in accumulation rate. Study patterns and causes of the onset of streaming flow in the catchments of selected large outlet glaciers draining through the Transantarctic Mountains will also be determined. The work will be conducted along the proposed US ITASE traverse route from Taylor Dome to South Pole. This route travels across the East Antarctic plateau, roughly parallel to the Transantarctic Mountains. Orthogonal satellite traverses are planned, each of which will follow a flow line of selected major outlet glaciers. The expected results include mass balance determinations for the Ross Ice Shelf sector of the East Antarctic Ice Sheet, an improved snow accumulation map for portions of East Antarctica, the deconvolution of ice dynamics effects from climate effects in ice core records, and an analysis of glaciological conditions near the onset of streaming flow leading to large outlet glaciers. The broader impacts of the proposed work include the collaboration with a multidisciplinary group of polar scientists, support of a graduate student and the production of results that will lead to an improved understanding of the Earth system from which sound planning and policy decisions can be based.
