Diagram of an avalanche

Fracture zone

The fracture zone is the point of origin of an avalanche. Avalanches break away on gradients of about 30-50°. If the fracture is localized, it is called a loose snow avalanche and if it is linear and sharp-edged, it is a slab avalanche.




The path is the zone of motion of an avalanche. It can be in sheet form or concentrated in gullies.



Deposition zone

The deposition zone is the area where the avalanche runs out and finally comes to a halt. This occurs on gradients below 10-20° or if the avalanche meets a counter slope. The length of the runout section depends on the type of snow and the speed of the avalanche at the start of the runout section. The deposited snow is called the avalanche cone or avalanche toe.