June 18,  19,  20   2003
 
 
 

03:00 PM - Thursday, June 19, 2003 - Amphitheater Darboux

Jacques Rappaz

Institute of Analysis and Scientific Computing
EPFL, Switzerland

jacques.rappaz@epfl.ch

Analysis and Numerical Simulation of Glacier Motions

The motion of a glacier is considered. At each time step, given the shape of the glacier, ice is modeled as an incompressible non-Newtonian fluid and a nonlinear elliptic problem has to be solved to obtain the horizontal velocity field. Then, the upper surface of the glacier is updated by solving a transport equation. Finite element techniques are used to compute the velocity field whereas the transport equation is solved using a Lax-Wendroff scheme. The goal of this talk is to present, in a first part, a two-dimensional model and some theoretical results concerning the existence, the uniqueness and the approximation of its solution. In the second part of the talk we will briefly present a three-dimensional model. Numerical results will be given and compared to experiments on Gries glacier (Wallis, Switzerland) between 1961 and 1991. Then, a prediction for 2021 will be proposed.