Avalanche or snowslide is an event in which a cohesive mass of snow slides loosens from the underlying layer, fractures and moves down a slope. Mechanical failure is a major trigger for avalanches. As the snow moves downslope, it gains in volume, mass and speed as it collects more snow en route. Avalanches are a natural hazard in mountainous regions. The recent flooding in Uttarakhand is being speculated to be triggered by an avalanche in the region a few days ago.