Lacroix Pascal, Belart J. M. C., Berthier E., Saemundsson T., Jonsdottir K. (2022). Mechanisms of landslide destabilization induced by glacier-Retreat on Tungnakvislarjokull Area, Iceland. Geophysical Research Letters, 49 (14), e2022GL098302 [11 p.]. ISSN 0094-8276.
Titre du document
Mechanisms of landslide destabilization induced by glacier-Retreat on Tungnakvislarjokull Area, Iceland
The massive worldwide deglaciation leads to more frequent slope instabilities in mountainous terrains. The physical processes leading to such destabilizations are poorly constrained due to little monitoring of dynamic parameters at the local scale. Here we study a very large slow-moving landslide (similar to 0.8 km(2)), on the flank of Tungnakvislarjokull glacier in Iceland. Based on a combination of remote sensing images, we monitor the landslide and glacier kinematics over 75 years, with a focus over the period 1999-2019 when rapid glacier wastage has been observed. The landslide accelerates from 2 to 45 m/yr in the 6 years following a sudden increase in glacier mass loss. This acceleration coincides with intense quake activity (Ml < 2.8), recorded by a regional seismic network. We show that this seismicity is caused by the landslide sliding on a rough surface. The evolution of the quake magnitudes suggests a progressive segmentation of the landslide mass during its acceleration.
