The role of lateral drag in the dynamics of Ice Stream B, Antarctica

Abstract

The partitioning of resistive force between the bed and sides of Ice Stream B, Antarctica, is obtained for three large areas that have been measured using repeat aerial photogrammetry. Problems associated with data errors and local variations in ice strength and velocity are reduced by considering the areally averaged budget of forces for each photo block. Results indicate that the bed under Ice Stream B must be very weak and unable to provide much resistance. Mechanical control on this ice stream emanates almost entirely from the lateral margins.