A frozen collision belt beneath ice:an overview of seismic studies around the Gamburtsev Subglacial Mountains,East Antarctica

AN MeijianDouglas A.WiensZHAO Yue

Institute of Geomechanics,Chinese Academy of Geological SciencesDepartment of Earth and Planetary Science,Washington University

摘要：The Gamburtsev Antarctic Mountains Seismic Experiment（GAMSEIS,2007-2010） was jointly conducted by the United States,China,and Japan during and after the International Polar Year 2007-2008.Broadband seismic stations were deployed across the ice-covered Gamburtsev Subglacial Mountains（GSM） and other previously unexplored areas in the interior of East Antarctica.Using GAMSEIS data,published results not only have revealed the deep structure of Antarctica,but also improved our understanding of the tectonic evolution of Antarctica and the supercontinent Gondwana,and of the relationship between geothermal heat flux and glaciers.This contribution draws together the major findings from recent studies,and also offers further investigation into the relationship between tectonic history and the East Antarctic Ice Sheet.The elevation of the GSM is largely supported by thickened crust,with Moho depths of ~60 km near the crest of the range.The GSM are underlain by thick（＞200 km） and cold continental lithosphere that likely formed after collision of two ancient crustal blocks during the pan-African orogeny.Heat flux results obtained from seismic inversion support a model of ice sheet basal melting that depends more strongly on bedrock topography than on geothermal heat flux,while ice surface and ice thickness are inversely correlated with heat flux.