Basal Conditions on Pine Island Glacier, West Antarctica

Abstract

Two Leica 1200 GPS receivers from NERC Geophysical Equipment Facility were used alongside two British Antarctic Survey GPS receivers. This allowed coverage between 55 km and 171 km along the centreline of Pine Island Glacier (PIG), West Antarctica and on one of its tributaries. Velocity, acceleration and elevation changes were measured. We demonstrated with a simple force-balance model that the section of PIG, 55 to 171 km inland, is steepening at a rate which provides an increase in driving stress of sufficient magnitude to produce the observed acceleration. If the perturbation causing this acceleration originated at the downstream end of the glacier it is likely that it has been transmitted rapidly upstream, by a diffusion process, faster than 10 years per 100 km. Current rates of thinning and acceleration are greater than any previously measured on PIG. A paper outlining these findings has been published online in discussion format and if successful under open review an edited version will be published in The Cryosphere journal.