A glossary of avalanche terms
- avalanche terrain
- Any terrain that possesses the characteristics that allows avalanches to occur if the snowpack is unstable. The most important characteristic is the angle of the slope. Most avalanches occur on slopes between 30 and 45 degrees.
- cornice
- A cornice is an overhanging and unsupported coif of snow that often forms on ridge lines lee to the prevailing wind.
- corn snow
- Snow that has undergone a melt / freeze cycle and is currently melted just enough that the surface is smooth resembling a thin pile carpet. It is great to ski!
- crown wall
- The vertical wall of snow that remains after slab failure.
- debris
- The remains of an avalanche that pile up in the run out or deposition zone and could include snow, ice, rocks, mud, trees . . . and anything else collected in the avalanche path.
- deposition or runout zone
- Is the area at the base of an avalanche, often low angle terrain, where the debris collects and a victim is most likely to be buried.
- graupel
- When snow crystals cannot be recognized because of rime, the grains are called graupel.
- lee or leeward
- Is the direction the wind is going to.
- metamorphism
- The change of form that snow crystals undergo once part of the snowpack. These changes will either strengthen the snowpack or weaken it.
- riming
- A deposit of ice from super-cooled water droplets. Rime can accumulate on the windward side of rocks, trees or structures, or on falling crystals of snow.
- runout zone
- See deposition zone.
- serac
- A serac is a part of the glacier that forms a tower of ice.
- slab or windslab
- One or more cohesive layers of snow under tension that may start to slide together.
- sloughs or sluffs
- A small avalanche usually made up of loose snow.
- snowpack
- The layers of snow that have accumulated from each snowfall, throughout a season.
- snow stability
- The strength of a snowpack and hence the probability under the right conditions that it will fail in the form of an avalanche.
- spindrift
- Windblown, powdery snow that typically funnels down gullies and has the effect of a small avalanche.
- stellar crystals
- New falling 6-fold, star like snow crystals.
- terrain trap
- A terrain feature that increases the consequences of getting caught in an avalanche. For example, gullies and crevasses increase the odds of a deep burial, and cliffs increase the odds of traumatic injuries.
- transceiver
- A transceiver is an electronic device much like a radio that can send or receive a signal.
- trigger
- The man made or natural force that sets off an avalanche.
- windward
- Is the direction the wind is coming from.
For more detailed definitions refer to the Canadian Avalanche Glossary, a fantastic resource.