Ice-flow properties at Dome Summit South, Law Dome, East Antarctica

Abstract

Ice-flow properties within a polar ice sheet are examined using the comprehensive data gathered from ice-core drilling by Australian National Antarctic Research Expeditions (ANARE) at Dome Summit South (DSS), on Law Dome, East Antarctica. Using the shear strain rates derived from borehole inclination measurements we demonstrate the need to modify the ice-flow relations to treat enhanced shear deformation deep within the ice sheet. We show that the relation between enhanced flow and the measured crystallographic properties is generally in accord with expectations, at least in the upper parts of the ice sheet, but it becomes clear that nearer to the bedrock the situation is more complicated. We also compare the observed shear strain-rate profile with results from a model that describes flow enhancement as a function of the applied stresses.