Avalanching

Avalanching refers to the rapid downslope movement of a mass of snow under gravity. In snow science and mountain safety contexts, an avalanche occurs when the snowpack becomes unstable and a layer or layer of snow detaches and slides down a slope. Avalanches are commonly categorized as slab avalanches, where a cohesive layer (slab) breaks away, and loose-snow avalanches, where loose snow is released at the start point and fans out as it accelerates. The triggering of avalanching can be natural, such as fresh snowfall, warming temperatures, or intense loading from wind, or caused by human activities that perturb the snowpack.

In a typical avalanche, a weak layer within the snowpack fails and releases a mass that accelerates and entrains more snow as it travels down the slope. The size, speed, and extent depend on the slope angle, terrain, snow properties, and the amount of snow on the slope. Debris and runout zones can extend far beyond the release point. Avalanches can be powerful enough to bury or injure people, damage infrastructure, and alter terrain. Forecasting relies on assessing snowpack stability, weather, and terrain; practitioners perform field tests such as stability tests and snow pits to identify weak layers and measure stability. Avalanche danger is routinely rated by forecast centers and guides to inform planning and travel decisions.

Safety measures include carrying and using avalanche rescue equipment (beacon, shovel, probe), traveling with companions, and following route-planning practices that reduce exposure to high-risk slopes. Education and training emphasize recognizing warning signs, such as cracking sounds or recent avalanche activity, and knowing when to postpone travel. While avalanches are a natural and recurring phenomenon in mountainous areas, informed planning and situational awareness can significantly reduce risk.