Studying the mass movements on the Earth's surface with seismic methods

Hazardous alpine mass movements like avalanches, debris flows and rock falls generate seismic signals, which can be detected with conventional earthquake seismometers. These signals are often emergent, weak and depend on the kind of mass movement as well as the local geology at the source, sensor and in between. This makes automatic detection of mass movement seismograms difficult. Here we investigate the use of intelligent algorithms to scan realtime data streams for mass movement signals. Given the rapidly growing data volume of national and international seismic data repositories and the increasing sensor coverage even in remote terrain, we aim to significantly enhance our ability to monitor and warn against Alpine natural hazards.

The debris flow observatory at Illgraben in Switzerland’s Valais is a focus of WSL’s mass movement seismology. The yearly occurrence of debris flows and the unstable slopes in the upper catchment area provide an ideal natural laboratory for testing our seismic detection algorithms. An important goal is to link seismic sensors with other equipment such as autonomous drones for an Internet of Things (Iot), which provides a new perspective for natural hazard monitoring.  Moreover, the WSL debris flow observatory delivers a wealth of data for investigating how dynamic properties of debris flows and other mass movements leave a signature in seismic records.