First airborne gravity results over the thwaites glacier catchment, West Antarctica

Abstract

Recent satellite observations of Thwaites Glacier in the Amundsen Sea Embayment, West Antarctica, have shown that the glacier is changing rapidly. The causes of its dynamic behavior are uncertain but are of concern because this glacier has the most negative mass balance of all Antarctic glaciers. To better understand Thwaites Glacier's subglacial setting, we conducted a multi-instrumented aerogeophysical survey of its catchment and present here the first gravity results. We employed a new gravimeter, and it performed well despite extreme conditions and an unusual survey design. The unleveled free-air gravity anomalies have a 2.3 mGal RMS error and a 9 km spatial resolution. Despite slightly higher than standard noise levels, the free-air anomalies correlate well with radar-derived subglacial topography. The new airborne gravity data assist in interpreting radar-identified bedrock features and are an ideal basis for future studies of subglacial geology and its control on the dynamics of Thwaites Glacier. Copyright 2008 by the American Geophysical Union.