Recent evolution of an ice-cored moraine at the Gentianes Pass, Valais Alps, Switzerland

International audience Lateral moraines located in permafrost environments often preserve large amounts of both glacier and periglacial ice. To understand how ice‐cored moraines located in high alpine environments evolve in a context of both glacier retreat and permafrost degradation, we performed 1...

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Bibliographic Details
Published in:Land Degradation & Development
Main Authors: Ravanel, Ludovic, Duvillard, Pierre-Allain, Jaboyedoff, Michel, Lambiel, Christophe
Other Authors: Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Université de Lausanne = University of Lausanne (UNIL), Institut de Géographie - Lausanne (IGUL)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2018
Subjects:
Ice
Online Access:https://hal-sde.archives-ouvertes.fr/hal-01881660
https://doi.org/10.1002/ldr.3088
Description
Summary:International audience Lateral moraines located in permafrost environments often preserve large amounts of both glacier and periglacial ice. To understand how ice‐cored moraines located in high alpine environments evolve in a context of both glacier retreat and permafrost degradation, we performed 11 terrestrial laser‐scanning measurement campaigns between 2007 and 2014 on a highly anthropogenic overprinted moraine prone to instability. Resulting comparison of the subsequent 3D models allowed to qualitatively and quantitatively analyze the morphological evolution of the moraine. The comparisons indicate a very high geomorphic activity of the moraine including large areas affected by downslope movements of blocks and 10 landslides with a volume between 24 ± 1 and 1,138 ± 47 m3. Data also indicated a very strong ice melt with a loss of ice thickness locally reaching 17.7 m at the foot of the moraine. These results, compared with resistivity and thermal measurements of the ground, suggest the combined role of ice loss at the foot of the moraine and the permafrost activity/warming in triggering these processes.