lawines

Lawines, commonly known in English as avalanches, are rapid flows or slides of snow down a slope. They can involve not only snow but ice, rocks, and debris, and may entrain trees or other material. The term "lawine" is the German word for avalanche; in English, the standard term is avalanche. People are most at risk on steep mountain terrain with persistent weak layers in the snowpack.

Avalanches occur when the weight of the snowpack exceeds its strength, often due to gravity acting on a destabilized layer. Common triggers include natural weather changes, such as heavy snowfall, rapid warming, rain on snow, or strong winds that load slopes with snow. Human triggers such as skiing, snowboarding, or explosives used in avalanche control can initiate release. There are two broad categories: loose-snow avalanches, which start as a single point and widen downslope; and slab avalanches, which involve a cohesive layer of slab snow breaking away and releasing.

Hazards include the speed and volume of the snow, terrain features, and exposure to runout zones. Warning signs include cracking sounds, hollow-sounding snow, and recent avalanche activity. Forecasts issued by national or regional avalanche centers rate danger on a scale from low to extreme and provide safety guidance. Prevention and safety measures include avoiding high-risk slopes, carrying beacons, probes, and shovels, and undertaking training in recognition of snowpack stability and rescue techniques. Research uses field tests, remote sensing, and computer models to improve forecasts and understand snow dynamics.