Mass Movement Monitoring and Warning at Spitze Stei (BE) Using Multi-Sensing Approaches

In recent years, the rock slope near «Spitze Stei» (Kandersteg, Switzerland) has exhibited elevated displacement rates exceeding 10 cm per day suggesting a growing instability of 20 million m³. Borehole data underline the presence of degrading permafrost and planes of enhanced gliding and shear deformation. However, these records are limited to point measurements and difficult to extrapolate over the entire slope. In this project, we conduct a passive seismic experiment to study subsurface processes on the Spitze Stei slope. We use interferometric noise analysis to detect small changes in elastic properties within the slope, which may be related to permafrost degradation and stability changes. Furthermore, we use the seismic data and a nearby infrasound antenna to monitor rock falls, avalanches and possibly sliding tremor reflecting frictional displacement within the slope.