Bed topography and surges in ice streams
Article first published online: 31 MAR 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 6, March 2004
How to Cite
2004), Bed topography and surges in ice streams, Geophys. Res. Lett., 31, L06401, doi:10.1029/2003GL018807.(
- Issue published online: 31 MAR 2004
- Article first published online: 31 MAR 2004
- Manuscript Accepted: 26 FEB 2004
- Manuscript Revised: 3 FEB 2004
- Manuscript Received: 9 OCT 2003
 Extensive bed topography at the scale of the ice thickness occurs frequently in the form of drumlins. By analogy with hard-bed sliding, ice flow over this type of topography leads to the generation of drag on the ice, particularly when ice flow is rapid. A crucial difference with classical Nye-Kamb sliding is that the upper, free surface of the ice has a significant effect on the sliding process through the formation of a standing wave. Using a theoretical model, we demonstrate that the presence of this wave introduces a non-linearity into the sliding motion which can lead to multiple sliding velocities for the same large-scale ice stream geometry, and that switches between these velocities can cause surging behavior.