Wednesday 29 April 2020

Avalanche kills skier on Mount Emmons, Colorado.

A skier has died after being caught in an avalanche at an altitude of about 3110 m above sealevel on the northeast slope of Mount Emmons, a 3780 m ridge mountain to the east of Crested Butte in the Elk Mountain Range (part of the Rocky Mountains) in Gunnison County, Colorado, on Tuesday 28 April 2020. The skier, a 40-year-old man whose identity has not been released, but who has been described as being local and highly experienced, was part of a group of four skiers on the slope, but was the only one caught by the avalanche. He was not buried by the event, and his companions attempted to provide first aid, but he died at the scene.

The approximate location of the 28 April 2020 Mount Emmons avalanche. Colorado Avalanche Information Center.

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.

This is the latest in a series of lethal skiing accidents in Colorado this month, despite pleas from local authorities for people to avoid travelling to the area during the Covid-19 epidemic, in order to free up local emergency services to deal with that crisis.

The location of Mount Emmons, Colorado. Google Maps.

See also...

https://sciencythoughts.blogspot.com/2020/04/skier-killed-by-avalanche-in-summit.htmlhttps://sciencythoughts.blogspot.com/2018/04/avalanche-kills-skier-near-aspen.html
https://sciencythoughts.blogspot.com/2017/12/explosion-injures-worker-at-collorado.htmlhttps://sciencythoughts.blogspot.com/2017/05/sinkhole-swallows-car-in-denver-colorado.html
https://sciencythoughts.blogspot.com/2015/06/police-vehicle-swallowed-by-sinkhole-in.htmlhttps://sciencythoughts.blogspot.com/2014/05/three-feared-dead-after-colorado.html
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