Modeling rockwall permafrost to understand periglacial rock slope failures

• Main Authors: Magnin, Florence, Deline, Philip, Duvillard, Pierre-Allain, Josnin, Jean-Yves, Legay, Alexandre, Ravanel, Ludovic
• Other Authors: Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), ANR-19-CE01-0018,WISPER,Processus thermo-mécaniques liés à l'eau et à la glace dans les fractures des parois alpines à permafrost(2019)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDE]Environmental Sciences; Ice; permafrost
• Online Access: https://hal.science/hal-04055509

International audience Rock slope failures are increasingly affecting high mountain rock walls, notably during hot summers (e.g. Ravanel et al., 2017). The common presence of ice in rock fall scars evidences the likely role of permafrost (i.e. ground which temperature is permanently ≤ 0°C) in rock fall triggering. Laboratory tests and mechanical models suggest that several permafrost-related processes influence bedrock stability (e.g. Krautblatter et al., 2013). Alteration of ice in joints due to the conductive heat transfer from the surface to depth, and advective heat flux by water infiltration in the fractures are thought to be the dominant processes in permafrost degradation (i.e. warming and thawing) causing rock wall destabilization. Water infiltration could also provoke high hydrostatic pressures at perched water table formed by the permafrost body and ice-filled fractures. To assess high mountain rock wall stability, it is thus important to know how permafrost is distributed, evolves, and interacts with hydrological processes. We here present recent developments in modelling rock wall permafrost and how models can help understanding rock slope destabilization at various space and time scales.