Changing basal conditions during the speed-up of Jakobshavn Isbræ, Greenland

Published: Jun 1, 2013 by The PISM Authors

Here, basal conditions for different years before and after the break-up of the tongue are inferred from surface velocity measurements to investigate the changes and to compare them with parameterizations of basal conditions commonly used in ice-sheet models. All inversions reproduce the overall pattern of observed surface velocities, which shows that, in general, our data and model choices are capable of reproducing the observations by only adjusting basal yield stress. In the lower 5 km of the glacier a clear trend from higher to lower basal yield stress values is visible.