A snow avalanche is the rapid mass movement of deposited snow that exceeds 100 m3 in volume and 50 metres in lenght. Based on how they move, avalanches can be subdivided into flowing avalanches and powder-snow avalanches.
When avalanches meet an obstacle, buildings and infrastructure can be destroyed by the resulting compressive forces. The destructive effect of avalanches can be further increased by the transport of trees and rocks.
Video: Slab avalanche