Basic Physics and the Shape of Glaciers

Abstract

Glaciers provide an impressive application of fluid mechanics and materials, and thermal physics. The basic microphysical properties of ice determine the shape of a glacier or ice cap. The order of magnitude of the maximum ice thickness is predicted using Weisskopf’s heuristic argument for the maximum height of a mountain, which involves only the specific latent heat of fusion and the acceleration of gravity. The local thickness of a glacier depends on the assumed ice rheology. The equations describing the steady state longitudinal glacier profile differ greatly for perfectly plastic ice and for ice following Glen’s law. Analytical solutions of these equations are derived: they fit well the data for ice caps but less so for alpine glaciers. Volume-area scaling, a major tool of glaciology, is discussed in relation with glacier profiles.