This award is for support to develop a time dependent analytical theory of three-dimensional glacier flow perturbations caused by small bedrock undulations and/or variation in basal resistance. The theory will be used to analyze data from the Siple Coast ice streams. The main objectives of the work will be: 1) to elucidate the cause of a number of observed surface undulations and local variation in the surface velocity field of Ice Stream D, and 2) to analyze theoretically the time scales associated with the buildup and decay of surface undulations and to test those theoretical concepts against measurements of surface and bedrock undulations from Ice Stream C. These objectives contribute to understanding how spatial variations in topography and resistance to slipping contribute to the support of the ice streams, the control of their speeds and their influence on changes in discharge from the West Antarctic ice sheet to the ocean. This work will be done in conjunction with NASA- Goddard Space Flight Center (Robert A. Bindschadler).
