Acceleration and interannual variability of creep rates in mountain permafrost landforms (rock glacier velocities) in the European Alps in 1995–2022

Andreas Kellerer-Pirklbauer (1) , Xavier Bodin (2) , Reynald Delaloye (3) , Christophe Lambiel (4) , Isabelle Gärtner-Roer (5) , Mylène Bonnefoy-Demongeot (6) , Luca Carturan (7) , Bodo Damm (8) , Julia Eulenstein (1) , Andrea Fischer (9) , Lea Hartl , Atsushi Ikeda (10) , Viktor Kaufmann (11) , Karl Krainer (12) , Norikazu Matsuoka (13) , Umberto Morra Di Cella (14) , Jeannette Noetzli (15) , Roberto Seppi (16) , Cristian Scapozza (17) , Philippe Schoeneich (18) , Martin Stocker-Waldhuber , Emmanuel Thibert (19) , Matteo Zumiani

1 Karl-Franzens-Universität Graz
2 EDYTEM - Environnements, Dynamiques et Territoires de Montagne
3 UNIFR - Université de Fribourg = University of Fribourg
4 UNIL - Université de Lausanne = University of Lausanne
5 UZH - Universität Zürich [Zürich] = University of Zurich
6 ECRINS - Risques gravitaires et cryosphère en montagne
7 Unipd - Università degli Studi di Padova = University of Padua
8 University of Vechta = Universität Vechta
9 Stuttgart State Academy of Art and Design
10 UTokyo - The University of Tokyo
11 TU Graz - Technische Universität Graz
12 Universität Innsbruck [Innsbruck]
13 Université de Tsukuba = University of Tsukuba
14 ARPA - Aosta Valley Regional Environmental Protection Agency
15 Swiss Federal Institute for Forest, Snow and Landscape Research WSL
16 UNIPV - Università degli Studi di Pavia = University of Pavia
17 SUPSI - Scuola universitaria professionale della Svizzera italiana = University of Applied Sciences and Arts of Southern Switzerland [Manno]
18 PACTE - Pacte, Laboratoire de sciences sociales
19 IGE - Institut des Géosciences de l’Environnement

Cryospheric long-term timeseries get increasingly important. To document climate-related effects on long-term viscous creep of ice-rich mountain permafrost, we investigated timeseries (1995–2022) of geodetically-derived Rock Glacier Velocity (RGV), i.e. spatially averaged interannual velocity timeseries related to a rock glacier (RG) unit or part of it. We considered 50 RGV from 43 RGs spatially covering the entire European Alps. Eight of these RGs are destabilized. Results show that RGV are distinctly variable ranging from 0.04 to 6.23 m a −1 . Acceleration and deceleration at many RGs are highly correlated with similar behaviour over 2.5 decades for 15 timeseries. In addition to a general long-term, warming-induced trend of increasing velocities, three main phases of distinct acceleration (2000–2004, 2008–2015, 2018–2020), interrupted by deceleration or steady state conditions, were identified. The evolution is attributed to climate forcing and underlines the significance of RGV as a product of the Essential Climate Variable (ECV) permafrost. We show that RGV data are valuable as climate indicators, but such data should always be assessed critically considering changing local factors (geomorphic, thermal, hydrologic) and monitoring approaches. To extract a climate signal, larger RGV ensembles should be analysed. Criteria for selecting new RGV-sites are proposed.

Domaines: Géomorphologie; Glaciologie

Andreas Kellerer-Pirklbauer, Xavier Bodin, Reynald Delaloye, Christophe Lambiel, Isabelle Gärtner-Roer, et al.. Acceleration and interannual variability of creep rates in mountain permafrost landforms (rock glacier velocities) in the European Alps in 1995–2022. Environmental Research Letters, 2024, 19 (3), pp.034022. ⟨10.1088/1748-9326/ad25a4⟩. ⟨hal-04474759⟩