A new ice thickness and bed data set for the Greenland ice sheet: 2. Relationship between dynamics and basal topography

Abstract

New data sets of bed and surface elevation have been combined with balance velocities, bed topography, and radar reflectivity to investigate the relationship between ice flow and bed conditions. It has been found that the bed topography affects the local driving stresses and initiates the onset of streaming flow in specific areas where there are large undulations. This onset region only appears significantly inland in three areas: the northeast Greenland ice stream, Kangerdlugssuaq Gletscher, and a region in the southwest associated with abnormally low driving stresses and an apparently unnamed but active glacier. Bed reflectance values below the northeast ice stream suggest that basal melting could be occurring along its length, and it seems likely therefore that the enhanced flow observed inland from the onset of streaming may be due, in part, to basal sliding. Copyright 2001 by the American Geophysical Union.