Blatten Glacier collapse 2025-05-30

3D Model

On Wednesday, the glacier known as Birchgletscher collapsed under the weight of rock and debris from rock avalanches on Kleines Nesthorn. The resulting debris buried most of the Swiss village Blatten in the Lötschental, Valais.

More information: https://polybox.ethz.ch/index.php/s/eazXqWn8z6rPNwo

Oblique imagery was collected by swisstopo on 2025-05-30 during a rapid response mapping flight, and published to https://www.rapidmapping.admin.ch/. The imagery was processed in Metashape and the model georeferenced to the swissALTI3D DEM and SWISSIMAGE Orthomosaic.

By comparing the swissALTI3D DEM and the created photogrammetric DEM, I estimate the total displaced volume to be approximately 10 Mio m³.

The processed files can be accessed here: https://drive.google.com/drive/folders/1JhhS84OsjAfN3STbMlRRd0b_wctRfibV

Copyright: Simeon Schmauß - created from BAFU/swisstopo Rapid Mapping oblique imagery, CC BY 4.0