Spatial and temporal variability, triggers and drivers of seismically detected rockfalls in the Reintal catchment, German Alps

Rockfalls are a substantial geohazard to human life and infrastructure in mountainous regions but we still lack detailed understanding of when and where rockfalls occur, and which environmental conditions lead to rockfall over diurnal, seasonal and annual timescales. This is due to the fact that direct observations in alpine landscapes are difficult to make and long, high-resolution time series of measurements are rare. Using seismic techniques, we can collect near-complete catalogues of geomorphic events and record their distributions in time and space. This allows studying the interaction of process domains, the role of various rockfall triggers, and lead and lag times with unprecedented detail.

We use the unique six-year long seismic dataset of the Reintal rockfall observatory in the German Alps to detect, classify and locate rockfalls in the Reintal catchment. This rockfall catalogue enables us to analyse the spatial and temporal variability of rockfalls spanning several orders of magnitude in size. We test the hypothesis that variations of rockfall in the Reintal catchment are dominated by seasonal patterns. In combination with weather data, we examine boundary conditions, drivers and triggers of rockfalls in this alpine catchment.