Influence of surface and subsurface heterogeneity on observed borehole temperatures at a mountain permafrost site in the Upper Engadine, Swiss Alps
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...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2012-04-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/6/517/2012/tc-6-517-2012.pdf |
| Summary: | 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. |
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| ISSN: | 1994-0416 1994-0424 |