Influence of surface and subsurface heterogeneity on observed borehole temperatures at a mountain permafrost site in the Upper Engadine, Swiss Alps

Schneider, Sina; Hoelzle, Martin; Hauck, Christian

doi:10.5194/tc-6-517-2012

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Journal article

Influence of surface and subsurface heterogeneity on observed borehole temperatures at a mountain permafrost site in the Upper Engadine, Swiss Alps

Schneider, Sina Alpine Cryosphere and Geomorphology (ACAG), Department of Geosciences, University of Fribourg, Switzerland
Hoelzle, Martin Alpine Cryosphere and Geomorphology (ACAG), Department of Geosciences, University of Fribourg, Switzerland
Hauck, Christian Alpine Cryosphere and Geomorphology (ACAG), Department of Geosciences, University of Fribourg, Switzerland

19.04.2012

Published in:

The Cryosphere. - 2012, vol. 6, p. 517-531

English Compared to lowland (polar) regions, permafrost in high mountain areas occurs in a large variety of surface and subsurface materials and textures. This work presents an eight-year (2002–2010) data set of borehole temperatures for five different (sub-) surface materials from a high alpine permafrost area, Murtèl-Corvatsch, Switzerland. The influence of the material on the thermal regime was investigated by borehole temperature data, the temperature at the top of the permafrost (TTOP-concept) and the apparent thermal diffusivity (ATD). The results show that during the last eight years, material-specific temperature changes were more significant than climate-induced temperature trends. At coarse blocky, ice-rich sites, no changes in active layer depth were observed, whereas the bedrock and the fine-grained sites appear to be highly sensitive to changes in the microclimate. The results confirm that the presence and growth of ice as well as a thermally driven air circulation within the subsurface are the key factors for the occurence and preservation of alpine permafrost.

Faculty

Faculté des sciences et de médecine

Department

Département de Géosciences

Language