One skier has died and another was injured after they were caught in an avalanche near Bovernier in the Swiss canton of Valais on Sunday 24 March 2019. Two other skiers were also caught by the avalanche, which occurred at an altitude of about 2800 m above sealevel, but escaped unscathed. The skier who died is reported to have suffocated after being buried beneath a metre and a half of snow. The incident happened less than 24 hours after another avalanche near Reichenau an der Rax in Lower Austria, which claimed the life of another skier, with a second victim airlifted to hospital with unspecified injuries. None of those involved in either incident have been namd yet.
Avalanches are caused by the mechanical failure of snowpacks; essentially when the weight of the snow above a certain point exceeds the carrying capacity of the snow at that point to support its weight. This can happen for two reasons, because more snow falls upslope, causing the weight to rise, or because snow begins to melt downslope, causing the carrying capacity to fall. Avalanches may also be triggered by other events, such as Earthquakes or rockfalls. Contrary to what is often seen in films and on television, avalanches are not usually triggered by loud noises. Because snow forms layers, with each layer typically occurring due to a different snowfall, and having different physical properties, multiple avalanches can occur at the same spot, with the failure of a weaker layer losing to the loss of the snow above it, but other layers below left in place - to potentially fail later.
Diagrammatic representation of an avalanche, showing how layering of snow contributes to these events. Expedition Earth.
See also...
Follow Sciency Thoughts on Facebook.
