Rock glaciers throughout the French Alps accelerated and destabilised since 1990 as air temperatures increased

• Published in: Communications Earth & Environment
• Main Authors: Marcer, Marco, Cicoira, Alessandro, Cusicanqui, Diego, Bodin, Xavier, Echelard, Thomas, Obregon, Renée, Schoeneich, Philippe
• Other Authors: Pacte, Laboratoire de sciences sociales (PACTE), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Sciences Po Grenoble - Institut d'études politiques de Grenoble (IEPG), Université Grenoble Alpes (UGA), 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), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Department of Geography Zürich, Universität Zürich Zürich = University of Zurich (UZH), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology; [SHS.GEO]Humanities and Social Sciences/Geography; Ice; permafrost
• Online Access: https://hal.science/hal-03249142; https://hal.science/hal-03249142/document; https://hal.science/hal-03249142/file/s43247-021-00150-6.pdf; https://doi.org/10.1038/s43247-021-00150-6

International audience Abstract Rock glaciers—ice-rich creeping landforms typical of permafrost mountain ranges—can develop an anomalous landslide-like behaviour called destabilisation. This behaviour is characterised by failure mechanisms (including cracks and crevasses) and increases in displacement rates by one to two orders of magnitude. Existing studies of this phenomenon have been limited to a small number of landforms and short time spans. Here, we systematically investigate the evolution of rock glacier kinematics over the past seven decades for the entire French Alps by combining observations of landform features indicative of the onset of destabilisation with data on displacements rates using aerial orthoimagery. We show that rock glacier velocities have significantly increased since the 1990s, concurrent with the development of destabilisation in 18 landforms that represent 5% of the 337 active rock glaciers. This pattern of activity correlates with rising air temperatures in the region, which suggests that a warming climate may play a role in this process.