Energenetics of Alpine Proglacial Geomorphic Processes

Abstract

Sediment budgets provide a means of quantifying transfers and storages within a landscape. Expressing sediment budget processes in terms of work and power provides a useful additional perspective on a sediment system. This paper discusses the merits of an energetics approach to quantifying sediment transfer processes in the Bas Glacier d'Arolla proglacial zone, Valais, Switzerland, during the 1987 melt-season. Energy estimates, based on sediment transfer processes, range over eight orders of magnitude. Both estimates of mass transfer and work emphasize the overwhelming importance of the meltwater channel and valley train within the proglacial sediment system. Based on energy and power magnitudes three sediment budget process subsets can be distinguished: (A) hillslope processes; (B) valley train margin processes; and (C) valley train channel processes. These process subsets represent a systematic spatial variation in energetics within the proglacial zone. Energetics together with sediment budget studies provides a valuable means of deciphering sediment system interactions. However, complexity inherent in sediment transport processes inhibits precise estimation of energy quantities.