Present‐day Antarctic ice mass changes and crustal motion

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Abstract
The peak vertical velocities predicted by three realistic, but contrasting, present‐day scenarios of Antarctic ice sheet mass balance are found to be of the order of several mm/a. One scenario predicts local uplift rates in excess of 5 mm/a. These rates are small compared to the peak Antarctic vertical velocities of the ICE‐3G glacial rebound model, which are in excess of 20 mm/a. If the Holocene Antarctic deglaciation history portrayed in ICE‐3G is realistic, and if regional upper mantle viscosity is not an order of magnitude below 1021 Pa·s, then a vast geographical region in West Antarctica is uplifting at a rate that could be detected by a future Global Positioning System (GPS) campaign. While present‐day scenarios predict small vertical crustal velocities, their overall continent‐ocean mass exchange is large enough to account for a substantial portion of the observed secular polar motion and time‐varying zonal gravity field .