VHP Photo Glossary: Debris avalanche or volcanic landslide
Sketch and animation by B. Myers
Debris avalanche
Debris avalanches are moving masses of rock, soil and snow that occur when the flank of a mountain or volcano collapses and slides downslope. As the moving debris rushes down a volcano and into river valleys, it incorporates water, snow, trees, bridges, buildings, and anything else in the way. Debris avalanches may travel several kilometers before coming to rest, or they may transform into more water-rich lahars, which travel many tens of kilometers downstream.
Case studies volcano debris avalanches (landslides)
Historical debris avalanches
- Mount St. Helens, Washington, 1980
- Otake volcano, Japan, 1984
- Huila Volcano, Colombia, 1994
- Casita Volcano, Nicaragua, 1999
Pre-historical debris avalanches
- Debris avalanches at Mount Rainier volcano, Washington
- Examples of volcanic landslide deposits from the United States and around the world
