Soil and rock temperatures in discontinuous permafrost: Gornergrat and unterrothorn, wallis, swiss alps

Abstract The areas studied display a rich periglacial geomorphology. The effects of seasonal and perennial ground frost are visible in the form of widespread solifluction phenomena, patterned ground and numerous rock glaciers. Soil and rock temperatures have been recorded, and permafrost distribution has been partly checked in selected areas with measurements of the basal snow temperature, and using geoelectrical and hammer seismic soundings. Permafrost is widespread on northerly exposed slopes, with a thickness of several decametres at 3100m a.s.1. Below 2800 m a.s.1. patchy permafrost occurs. A model for vertical permafrost distribution is presented and an altitude of 3500 m a.s.1. is suggested for the lower limit of continuous permafrost. As a result of aspect, soil and rock temperature fluctuations are different on northern and southern slopes. This induces differences in vegetation cover, debris production and geomorphological processes.