The forces or stresses in a glacier are separated into lithostatic and resistive components. The lithostatic component is the weight of ice and gradients in it cause glacial motion as described by the driving stress. The remaining stresses oppose the motion and in assessing glacial stability it is important to determine which of the several potential resistive forces are most important, Data relating to the stresses driving and resisting the flow of the West Antarctic Ice Sheet are discussed. The driving stress is readily calculated and it shows an almost exponential decrease from the inland ice, along Ice Stream B, and across the Ross Ice Shelf to the calving edge. Prior work shows that basal drag restrains inland ice and that the backstress on ice shelves originates at islands, shoals, and the sides. The restraints on ice streams are not at present known, but basal drag, side drag, and back-pressure from the interstream ridges where the inland ice funnels into ice streams, are potential controls.
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- Force Budget of Ice Sheets
I. M. Whillans
- Springer Netherlands