Multi-decadal (1953–2017) rock glacier morphodynamics analysed by high-resolution topographic data in the Upper Kauner Valley, Austria

• Main Authors: Fleischer, Fabian, Haas, Florian, Piermattei, Livia, Pfeiffer, Madlene, Heckmann, Tobias, Altmann, Moritz, Rom, Jakob, Stark, Manuel, Wimmer, Michael H., Pfeifer, Norbert, Becht, Michael
• Format: Text
• Language: English
• Published: 2021
• Subjects: permafrost
• Online Access: https://doi.org/10.5194/tc-2021-77; https://tc.copernicus.org/preprints/tc-2021-77/

Permafrost is being degraded worldwide due to the change in external forcing caused by climate change. This has also been shown to affect the morphodynamics of active rock glaciers. We studied these changes, depending on the analysis, on nine or eight active rock glaciers with different characteristics in multiple epochs between 1953 and 2017 in Kauner Valley, Austria. A combination of historical aerial photographs and airborne laser scanning data and their derivatives are used to analyse surface movement and 3D displacements. In general, the studied landforms show a significant acceleration of varying magnitude in the epoch 1997–2006 and a volume loss to varying degrees throughout the investigation period. Besides, we detect rock glaciers that show indication of inactivation. By analysing meteorological data (temperature, precipitation and snow cover onset and duration), we are able to identify possible links to these external forcing parameters. The combined investigation of horizontal and vertical 3D displacements shows that these are temporally decoupled on some rock glaciers. The catchment-wide survey further reveals that, despite the general trend, timing, magnitude and temporal peaks of morphodynamic changes indicate a slightly different sensitivity, response or response time of individual rock glaciers to fluctuations and changes in external forcing parameters.