Fracture line

Curtis Pawliuk

A fracture line, or crown.

The line that forms the outer extent of the slab fracture of a slab avalanche. Fracture lines outline the top of the start zone and often part of the flanks of a slab avalanche after it has released. They often connect a line between likely trigger points and locations of heightened strain on the snowpack, such as convexities, as well as thinner or perforated snowpack areas. The upper part of a fracture line is commonly referred to as a crown.