Scapozza, Cristian and Lambiel, Christophe and Baron, Ludovic and Marescot, Laurent and Reynard, Emmanuel (2011) Internal structure and permafrost distribution in two alpine periglacial talus slopes, Valais, Swiss Alps. Geomorphology, 132 (3-4). pp. 208-221.
Full text not available from this repository.Abstract
In order to determine the spatial extension and the characteristics of permafrost within alpine talus slopes, two sites located in the western part of the Swiss Alps were studied using borehole drilling and electrical resistivity tomography (ERT) profiles. Three boreholes were drilled along an upslope–downslope transect in both talus slopes. In both sites, frozen sediments are present only in the two lowest boreholes, whereas the upper borehole does not present ice. This stratigraphy is confirmed by ground temperatures registered in the boreholes. In each site, three upslope–downslope ERT profiles were crossed with five, respectively four horizontal ERT profiles. All the upslope–downslope profiles show a difference in resistivities between the upper and lower parts of the slope, where a large resistive body with values higher than 35 kΩm is present. In the uppermost part of the profiles, the resistivities are lower than 10–15 kΩm. The borehole data allowed the stratigraphy obtained from the ERT inverted profiles to be validated, with regards to the distribution of frozen sediments as well as the depth of the detected structures. The results confirm that, in the two studied sites, permafrost is present in the lower sections of the talus slopes, whereas it is absent in the upper parts. Finally, the analysis of the talus structure showed that the permafrost stratigraphy, and in particular the ice content, may be an important element of interpretation of the palaeoclimatic significance of an alpine talus slope.
| Item Type: | Scientific journal article, Newspaper article or Magazine article |
|---|---|
| Uncontrolled Keywords: | Permafrost; Talus slope; Borehole drilling; Electrical resistivity tomography (ERT); Swiss Alps |
| Subjects: | Physical sciences > Geology > Earth science > Geoscience Physical sciences > Geology > Earth science > Quaternary studies Physical sciences > Geology > Geophysics |
| Department/unit: | Dipartimento ambiente costruzioni e design > Istituto scienze della Terra |
| Depositing User: | Cristian Scapozza |
| Date Deposited: | 08 Mar 2013 09:34 |
| Last Modified: | 11 May 2016 07:12 |
| URI: | http://repository.supsi.ch/id/eprint/2150 |
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