Local resident Pierre-Emmanuel Zufferey recorded this powerful debris flow on July 12 in the Illgraben area of Switzerland as mud, water and rocks came thundering down the hillside channel.
SUSTEN, Switzerland – A recent massive debris flow thundered down a Swiss mountain channel, creating a roaring sound as the wall of water, rocks and mud shook.
Local resident Pierre-Emmanuel Zufferey captured the spectacular show on July 12 in the Illgraben valley near the Switzerland village of Susten. For the past 24 years, the active geological site has been home to debris-flow observation measurements by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).
Debris flows are a combination of landslides and flash flooding that can occur when heavy rainfall moves quickly down a valley.
The Illgraben debris flow seen on July 12, 2024.
Zufferey wrote that there would be “no chance” of escape from the powerful water and debris. The video speaks for itself: no person standing near the hillside would be safe as the water pushed boulder-sized rocks down the slope.
Data from Illgraben is being used to develop debris flow erosion models and improve understanding of debris flows, according to the WSL.
The Illgraben site is unusual because it averages three to five debris flows a year when they are rare elsewhere.