Installation of a shallow borehole network and monitoring of the ground thermal regime of a high alpine discontinuous permafrost environment, Eastern Swiss Alps

Abstract

Permafrost is known to respond to changes in atmospheric temperatures but our knowledge of the scale and the processes involved are still not fully understood, especially not when the surface is other than bedrock. In order to gain a better understanding of the influence of the surface and ground characteristics on the thermal regime of the active layer, boreholes were drilled in the high alpine discontinuous permafrost in the Murtèl-Chastelets area, Eastern Swiss Alps, and instrumented with chains of thermistor arrays. Five shallow boreholes were drilled during the summer of 2002, adding to the network of the existing four boreholes. Data from the first year of this multi-annual study demonstrate a pronounced thermal offset for loose material composed of gravel or boulders. Also, the thermal diffusivity was calculated over the summer period, adding to the understanding of the spatial discontinuity in the Alpine permafrost.