Distribution of Mountain Permafrost, Fontanesses Basin, Valaisian Alps, Switzerland

In the Fontanesses area (Valais-Swiss Alps), 237 measurements of temperatures at the base of winter snowpack (BTS) and 29 DC resistivity soundings were carried out between 1993 and 1995. BTS measurements ranged from −0.9 to −8.2°C. Active layer thicknesses calculated from the BTS values are from 0.9 to 5.2 m. The BTS values indicate that the lower altitudinal limit of discontinuous permafrost is about 2700–2900 m ASL for the generally south-oriented slope of the Fontanesses. Electrical resistivities calculated from a geoelectric model vary from 0.1–15 kΩm for the active layer to 38–1500 kΩm for permafrost containing ice. On rock glaciers, the active layer is between 2 and 5 m thick while the permafrost has a minimum thickness of about 30 m.