Quantification of sediment transport by rockfall and rockslide processes on a proglacial rock slope (Kaunertal, Austria)

Rockfalls and rockslides are significant geomorphic processes on high alpine proglacial rock slopes. In this study, we quantitatively evaluate sediment transport on a recently deglaciated rock slope that is directly connected to the shrinking Gepatschferner glacier, by multi-temporal terrestrial and airborne LiDAR observations. According to the LiDAR measurements, sediment transport by gravitational mass movements on this single proglacial rock slope (0.2 km2) yielded 159 GJ/a geomorphic work. The most significant part (141 GJ/a) was released by rockfall while 18 GJ/a were performed by the sliding activity of a 1,250,000 m3 large unstable rock mass. The results indicate that slope development and talus formation in proglacial environments may be a rapid process despite of being caused by continuous rockfall activity over several millennia.