Warming permafrost and active layer variability at Cime Bianche, Western European Alps
- Pogliotti, P. Environmental Protection Agency of Valle d'Aosta, Saint Christophe, Italy
- Guglielmin, M. Department of Theoretical and Applied Sciences, Insubria University, Varese, Italy
- Cremonese, E. Environmental Protection Agency of Valle d'Aosta, Saint Christophe, Italy
- Morra di Cella, U. Environmental Protection Agency of Valle d'Aosta, Saint Christophe, Italy
- Filippa, G. Environmental Protection Agency of Valle d'Aosta, Saint Christophe, Italy
- Pellet, C. Department of Geosciences, University of Fribourg, Switzerland
- Hauck, Christian Department of Geosciences, University of Fribourg, Switzerland
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08.04.2015
Published in:
- The Cryosphere. - 2015, vol. 9, no. 2, p. 647–661
English
The objective of this paper is to provide a first synthesis on the state and recent evolution of permafrost at the monitoring site of Cime Bianche (3100 m a.s.l.) on the Italian side of the Western Alps. The analysis is based on 7 years of ground temperature observations in two boreholes and seven surface points. The analysis aims to quantify the spatial and temporal variability of ground surface temperature in relation to snow cover, the small-scale spatial variability of the active layer thickness and current temperature trends in deep permafrost.Results show that the heterogeneity of snow cover thickness, both in space and time, is the main factor controlling ground surface temperatures and leads to a mean range of spatial variability (2.5 ± 0.1 °C) which far exceeds the mean range of observed inter-annual variability (1.6 ± 0.1 °C). The active layer thickness measured in two boreholes at a distance of 30 m shows a mean difference of 2.0 ± 0.1 m with the active layer of one borehole consistently deeper. As revealed by temperature analysis and geophysical soundings, such a difference is mainly driven by the ice/water content in the sub-surface and not by the snow cover regimes. The analysis of deep temperature time series reveals that permafrost is warming. The detected trends are statistically significant starting from a depth below 8 m with warming rates between 0.1 and 0.01 °C yr⁻¹.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Géosciences
- Language
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- English
- Classification
- Hydrology
- License
- License undefined
- Identifiers
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- RERO DOC 255838
- DOI 10.5194/tc-9-647-2015
- Persistent URL
- https://folia.unifr.ch/unifr/documents/304291
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