Evaluating the destabilization susceptibility of active rock glaciers in the French Alps

Abstract : In this study, we propose a methodology to estimate the spatial distribution of destabilizing rock glaciers, with a focus on the French Alps. We mapped geomorpho-logical features that can be typically found in cases of rock glacier destabilization (e.g. crevasses and scarps) using orthoimages taken from 2000 to 2013. A destabilization rating was assigned by taking into account the evolution of these mapped destabilization geomorphological features and by observing the surface deformation patterns of the rock glacier, also using the available orthoimages. This destabilization rating then served as input to model the occurrence of rock glacier destabilization in relation to terrain attributes and to spatially predict the susceptibility to destabilization at a regional scale. Significant evidence of destabilization could be observed in 46 rock glaciers, i.e. 10% of the total active rock glaciers in the region. Based on our susceptibility model of destabilization occurrence, it was found that this phenomenon is more likely to occur in elevations around the 0 degrees C isotherm (2700-2900ma. s.l.), on north-facing slopes, steep terrain (25 to 30 ffi) and flat to slightly convex topographies. Model performance was good (AUROC = 0.76), and the susceptibility map also performed well at reproducing observable patterns of destabilization. About 3 km(2) of creeping permafrost, or 10% of the surface occupied by active rock glaciers, had a high susceptibility to destabilization. Considering we observed that only half of these areas of creep are currently showing destabilization evidence, we suspect there is a high potential for future rock glacier destabilization within the French Alps.
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https://hal.archives-ouvertes.fr/hal-02011802
Contributeur : Christine Maury Referent Hal Edytem <>
Soumis le : vendredi 8 février 2019 - 11:12:22
Dernière modification le : dimanche 10 février 2019 - 01:02:31

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  • HAL Id : hal-02011802, version 1

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Marco Marcer, Charlie Serrano, Alexander Brenning, Xavier Bodin, Jason Goetz, et al.. Evaluating the destabilization susceptibility of active rock glaciers in the French Alps. The Cryosphere, Copernicus 2019, 13 (1), pp.141-155. 〈hal-02011802〉

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