How does an avalanche happen and why?

Answer 1

AvalanchesAn avalanche occurs when a mass of snow falls down a mountainside. That is because new snow (which is not wet) accumulates on a more heavy snow layer. Since the new snow layer is not compact, it could slide down toward the base of the mountain.

Avalanches could be triggered by loud noise (yells, firearm shots, etc.). Skiers, snowboarders and climbers could also cause an avalanche.

There are two ways to reduce avalanche risks: by installing snowsheds or by triggering controlled avalanches. These protection fences are made of rocks, soil and other materials. They prevent avalanches to fill trails used by humans.

Controlled avalanches cause the accumulated snow to fall down before it could trigger avalanches by itself. When nobody is in danger, explosives are used to produce a loud noise that causes an avalanche.

Avalanches could be seen every winter in mountainous regions of Québec. Fortunately, they do not often occur near inhabited areas.

What to Do During an AvalancheDuring the winter, do not venture in the mountain without an adult.

If you walk in a trail after a snow fall, do not walk in the middle of it, but rather on the side. Avalanches always fall down in the middle of the path; thus, if you are on the side, the risks of being hit by the avalanche are lower.

Answer 2

An avalanche occurs when a layer of snow collapses and slides downhill. This can be triggered by factors such as weather conditions, snowpack stability, slope angle, and human activity. The weight of the accumulating snow destabilizes the underlying layers, causing them to fracture and release down the mountainside.