Field Experiments to Determine the Effect of a Debris Layer on Ablation of Glacier Ice

Ablation of glacier ice has been observed with artificial debris layers prepared with Ottawa sand (ASTM C-109) ranging from 0.01 to 0.1 m thick. Data on external variables observed during the experiments and determination of physical constants of the debris layers have allowed the testing of a proposed simple model. Theoretical predictions compare favourably with the observations. Discussion is extended to a proposal for a simple method by which ablation under a debris layer could be estimated even if the thermal conductivity or thermal resistance of the material were unknown.