Towards a better understanding of debris flow sediment sources: Monitoring of an active rock slope at Spitze Stei, Switzerland

Rapid process cascades can lead to destructive debris flows. Identifying and characterizing the processes conditioning debris-flow occurrence will strongly contribute mitigation of hazards. In recent years, rock slope near “Spitze Stei”, in Kandersteg region, Switzerland, has exhibited elevated displacement rates exceeding 10 cm per day, suggesting a growing instability up 20 million m 3 . The accumulated sediments at bottom Spitze Stei are mobilized as flows by melting snow heavy summer precipitations. Here, we use seismology combined with an intelligent algorithm automatically detect rockfall landslides slope. These mass movements act primary sediment sources delivering debris-prone channel. Our initial results quantify movement activity before two flow events that occurred 2022 identify their triggers. Such analysis towards mitigating hazards extending warning time, especially for triggered factors other than precipitation.