Snow control on active layer and permafrost in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l, Mont Blanc massif).

• Main Authors: Magnin, Florence, Westermann, Sebastien, Pogliotti, Paolo, Ravanel, Ludovic, Deline, Philip
• Other Authors: Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry ), Department of Geosciences Oslo, Faculty of Mathematics and Natural Sciences Oslo, University of Oslo (UiO)-University of Oslo (UiO), ARPA Valle d'Aosta (Aosta Valley Regional Environmental Protection Agency), Aosta Valley Regional Environmental Protection Agency (ARPA), European Geosciences Union
• Format: Other/Unknown Material
• Language: English
• Published: HAL CCSD 2016
• Subjects: geo; envir; Mont Blanc; Piton; Piton Central; permafrost
• Online Access: https://hal-sde.archives-ouvertes.fr/hal-01788521

International audience Processes that control climate-dependent rockfall from permafrost-affected rock slopes are still poorly understood.In this study, we present the results of a Wireless Sensor Network, integrated within the Swiss project PermaSenseand developed in 2012, to measure rock temperature and geotechnical parameters in the steep rockwalls of theAiguille du Midi (AdM, 3842 m a.s.l., Mont Blanc massif, France). Accessible year round by cable car, the AdMcomprises two main peaks: (i) the Piton Nord with the cable car arrival station, where 4 crack-meters are placed onfour major fractures, and (ii) the Piton Central with many touristic infrastructure, equipped with three 10-m-deepboreholes with 15 temperatures sensors since 2009, and where 2 crack-meters are installed along a major fracture.Three major kinematic regimes are observed: (i) opening of clefts when the rock temperature becomes positive,followed by closing during the cold period, (ii) summer opening continued by a winter opening, and (iii) closingduring the warm period followed by opening in winter.