Evaluating the destabilization susceptibility of active rock glaciers in the French Alps
<p>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 geomorphological features that can be typically found in cases of rock glacier destabilization (e.g. crevasses and scarps) using orthoimage...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-01-01
|
| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/141/2019/tc-13-141-2019.pdf |
| Summary: | <p>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 geomorphological 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 <span class="inline-formula"><sup>∘</sup></span>C isotherm (2700–2900 m a.s.l.),
on north-facing slopes, steep terrain (25 to 30<span class="inline-formula"><sup>∘</sup></span>) and flat to slightly
convex topographies. Model performance was good (AUROC <span class="inline-formula">=</span> 0.76), and the
susceptibility map also performed well at reproducing observable patterns of
destabilization. About 3 km<span class="inline-formula"><sup>2</sup></span> 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.</p> |
|---|---|
| ISSN: | 1994-0416 1994-0424 |