Investigating the effects of meteorological conditions on landslide formation in a high-arctic glacier basin using terrestrial laser scanning (Ny-Ålesund, Svalbard)

Landslide processes are one of the dominant agents of erosion and sediment transport in alpine terrain, which often pose a significant risk to communities and infrastructure around the world. Climate change generates a wide range of processes such as glacier retreat, permafrost degradation or changing precipitation patterns, which are projected to decrease the stability of mountain slopes and thus will lead to increased landslide activity. However, the empirical evidence is lacking as meteorological boundary conditions altered by climate change, may have different and often contrasting effects on landslide formation and activity. As a result of the Arctic amplification, high-arctic environments are an important field laboratory for investigating current and future landslide processes.

The ongoing paraglacial response of sediment-mantled slopes through landslide processes has been assessed and mapped around the globe. However, investigations on the impact of meteorological factors on shallow landslide formation modifying sediment-mantled slopes in the surroundings of retreating glaciers is in many cases not possible due to the lack of long-term high-resolution terrain data. The Austre Lovénbreen glacier basin in Svalbard (Norway) is a particularly relevant location to study the modification of slopes through landslides, as the area has been affected by the recent global warming characterized by the greatest temperature increase during the last three decades.

The objectives of this study are i) to provide data utilizing multi-temporal high-resolution terrestrial laser scans of the glacier and the surrounding slopes, ii) identify and quantify landslide processes found on sediment-mantled slopes, iii) investigate failure mechanisms and derive a conceptual model describing the adaptation of the periglacial talus slopes to the retreat of the glacier and iv) investigate the driving factors for the temporal and spatial evolution of landslides in the Austre Lovénbreen Basin.

The Austre Lovénbreen glacier basin represents a highly dynamic environment, which is in an unstable state, caused by the rapid retreat of the glacier and by climatic conditions. We show that, in contrast to the established literature, shallow debris slides are the primary source of sediment transport on steep sediment-mantled slopes in a high-arctic environment and that meteorological parameters control their spatial and temporal evolution.