Project: Landslides in a changing climate

A direct link between the current trend towards warm climate and decreasing slope stability has recently been suggested based on an increasing incidence of landslides in polar marginse. In addition to the common triggers of landslides, increased precipitation, permafrost degradation and rapid isostatic rebound become determining preconditioning factors for slope instability in polar margins. However, the climate link to the landslide occurrence remains to be evaluated in examples from the geological past.

The detailed study of the mass transport deposits in Karrat Fjord and Vaigat has the potential to reveal the frequency and magnitude of landslides (or rock avalanches) and tsunamis in West Greenland, their relation to climate change and the variability of the Greenland ice sheet, and their impact on benthic habitats. Thus, we propose to utilize the nearshore landslide record in West Greenland, and published climate studies, to bridge knowledge gaps on climate-related triggers for slope instability, and the implications of the current trend of climate change.

Expeditions onboard RV Sanna in 2019 and 2021 collected ~4000 km of seismic, sub-bottom and swath bathymetry data within Karrat Fjord and Vaigat, with particular focus on areas of offshore exposed slope failures. Swath bathymetry data from Merian 2017, OMG 2015 and JCR175, and LAKO transits have been made available for this project in collaboration with national and international partners. In addition, 29 gravity cores of up to 6 m were recovered during Sanna’s expeditions.

Morpho-structural and seismic-stratigraphic analyses of the geophysical data from Karrat Fjord and Vaigat will reveal the geological history of landslide occurrences. Seafloor geomorphology will be analysed to evaluate the most recent sedimentary processes and the spatial distribution of benthic habitats.

The project objectives are within the scope of Geocenter Denmark by investigating climate change and geohazards to maintain a resilient society. They also contribute to the United Nations (UN) Sustainable Development Goals [13: Climate; 11: Sustainable communities; 14: life in the ocean].