Map analysis techniques for glaciological applications

Abstract

This paper presents map analysis of digital elevation models for glaciological applications. The approach has been to combine spatial information describing the geometry of the glaciers with physical models of glaciological processes and to adjust empirical parameters to give a best fit with field observations. This applies to description of the basal shear stress and the resulting flow due to deformation of the ice. The outputs display spatial distributions, which can be adjusted to field observations through flexible routines of averaging the geographical information. Further, this approach is applied to description of the potential driving water along the bed, defined by the basal topography of the glacier and a model assuming that the basal water pressure is related to the thickness of the ice. The results produce predictions of the location of subglacial waterways and their drainage basins, which can be adjusted to field observations by choice of an empirical parameter, giving the basal water pressure as a fraction of the ice overburden pressure. A routine is presented that integrates the meltwater contribution downglacier to the various river outlets, given the glacier surface ablation.