Regional Mountain Conference

In the last few decades, the frequency of large alpine mass movements has seen a substantial increase causing important damage to infrastructure. This calls for the development and maintenance of inventories to track such changes. Landslide and rockfall inventories are typically limited to a single class of events, localized to a specific region or research objective, available only with large delays, and frequently the data contains considerable observer bias [2]. Automated and near real-time detection of large mass movements using seismic infrastructure networks have been proposed at a national level, e.g. for Switzerland [1]. Here, a validation mechanism using an expert group of local observers is used to validate detected events post fact. This allows to (i) detect, localize and classify large rockfalls and landslides at a regional level, (ii) reduce observer bias wrt. manually curated catalogs, and (iii) provide frequent updates with minimal delay to an inventory. For example, for the main collapse of the Birchgletscher/Nesthorn in Blatten CH on May 28th, 2025, the first analysis of Magnitude 3.1 was available at 15:39:37 CEST, merely 14 minutes after the event occurred. 

In this work, we first analyze the events cataloged using seismic detection over the past two decades in Switzerland under the auspices of the Swiss Seismological Service and the Rockfall Mailing List Collaboration. In a second step, we extend this to the whole Alpine Arc with events from national seismic inventories from Switzerland, Italy, Austria, France and Germany, spanning from 1990 to present. We compare this data to catalogs derived from personal observer networks [2], scientific literature, and personal communications. The result is an inventory of mass movements containing information about the location, time and magnitude of all events. The joint multi-source inventory is a first step towards a comprehensive and up-to-date statistical analysis of the impacts of climate change on the occurrence of high alpine mass movements in the European Alps. 

[1] Kastli, P., Clinton, J., Kraft, T., Diehl, T., and Haslinger, F.: A near-real-time public mass movement catalogue for Switzerland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19568, https://doi.org/10.5194/egusphere-egu25-19568, 2025.

[2] PERMOS Rockfall Catalog. https://www.permos.ch/data-portal/rock-falls, accessed January 2025.