MAGIC-DMLMeasuring/Mapping/Modeling Antarctic Geomorphology and Ice Change in Dronning Maud Land: The German ice sheet modeling component

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This proposal presents the core modeling component of the international collaborative project MAGIC-DML linking researchers from Sweden, USA, Germany, UK, and Norway. MAGIC-DML overall focuses on reconstructing the long-term pattern and timing of ice-surface elevation changes across Dronning Maud Land (DML) in the East Antarctic Ice Sheet (EAIS). The modeling component of MAGIC-DML will combine past ice elevations across DML determined by field mapping and cosmogenic dating of glacial landforms on nunataks with data from other areas in East Antarctica and high-resolution ice sheet modeling to provide insights into EAIS changes and long-term regional climate evolution. Our numerical experiments will test a large number of climate model products in order to evaluate the following hypotheses:- The inland sectors of the EAIS have experienced long-term reductions in ice-surface elevation since the Pliocene;- The ice sheet last retreated from its maximum extent in DML after 25 thousand years ago (ka), at which time the ice surface was hundreds of meters higher near the coast, but no higher and perhaps lower across most of continental East Antarctica.An approach combining ice sheet modeling with field evidence and climate model reconstructions will set a limit on a relative contribution of the EAIS to past sea level variations and reduce large uncertainties in past climate conditions across Antarctica. As part of this, we will quantify the response of the EAIS margin to warmer-than-present climate conditions, such as inferred for the Pliocene and Marine Isotope Stages 11c (420 - 400 ka) and 5e (124 - 119 ka), providing analogs for the EAIS response to anticipated future climate warming.