The aims of this study were to determine the surface velocities in the ablation region of the Victoria Upper Glacier, and from these measurements to calculate the between point strains, and the strain rates of areas within the measured array. The strain results were also used to determine the nature of cold-based glacier behaviour, through the comparison of results with Glens Flow Law.
The response of glacier systems to past and future climate change relates to glacier characteristics. One such factor is the deformation rate achieved by the glacier. Deformation of ice is achieved by three processes, namely internal deformation, basal sliding and subglacial sediment deformation. Although these three processes are affected by many parameters, they are primarily controlled by the thermal and hydrological regimes of the glacier. At present, there is limited understanding in the glaciological community about the behaviour of cold-based glaciers. The mechanisms that facilitate glacier motion in cold conditions are not well understood, nor are the rates of deformation that characterise cold-based glaciers. This study examines the surface and basal strain rates in the ablation zone of the Victoria Upper Glacier. Using GPS to measure changes in stake locations on the surface, and plumbline displacement measurements in the basal region, velocities at both the surface and the bed are measured, and in the case of the surface results, transformed into strain rates. These results were then compared with the theoretical strain rate value calculated from Glen's flow law, to determine the behaviour of the glacier.
MacDonell, S. 2003. Cold-based glacier behaviour: Victoria Upper Glacier, Antarctica. Unpublished BSc (hons) in Geography, University of Otago, Dunedin, New Zealand.