Fleischer, F., Haas, F., Altmann, M., Rom, J., Ressl, C., & Becht, M. (2023). Glaciogenic Periglacial Landform in the Making—Geomorphological Evolution of a Rockfall on a Small Glacier in the Horlachtal, Stubai Alps, Austria. Remote Sensing, 15(6), Article 1472. https://doi.org/10.3390/rs15061472
alpine deglaciation; demise of a small glacier; supraglacial debris; post-glacial landscape evolution
en
Abstract:
Deglaciation in high mountain areas signifies the transition from glacial to periglacial conditioned landscapes. Due to the reduced melt rate of debris-covered glacier ice, these areas of the glacier may persist long after the surrounding glacier has melted, resulting in the formation of distinct post-glacial landforms. In this study, we examine the geomorphological evolution and potential future development of a 19,267 m³ ± 204 m³ rockfall from the permafrost-affected headwall on the low-elevated Zwieselbachferner in the Horlachtal, Stubai Alps, Austria. The analysis uses multi- epochal remote sensing data, including photogrammetrically and airborne laser scanning-derived digital elevation models, orthophotos, and satellite data, covering a period from the initial rockfall in 2003/2004 to 2022. The data reveals that the rockfall event resulted in the formation of a supraglacial debris layer of varying thickness, spanning an area of 15,920 m². Subsequently, 13 further rockfalls ranging from 67 m³ ± 6 m³ to 4250 m³ ± 121 m³ were detected. The mean ice thickness of the debris-covered area only slightly decreased between 2006 and 2022, in contrast to the surrounding glacier, whose thickness and length have strongly decreased. This results in the formation of a steep front and flanks that become increasingly covered by debris redistribution. The study suggests that the glacier ice covered by rockfall-derived debris will remain as a periglacial landform of glacial origin after the complete melting of the surrounding glacier.
en
Research Areas:
Environmental Monitoring and Climate Adaptation: 100%