Natural Hazard: Avalanche

By: Karli Elit

Avalanche

(n) a mass of snow, ice, and rocks falling rapidly down a mountainside.


Information

How it Originates or Forms:

Avalanches form from the snow responding to the pull of gravity. They are born from a weakness in the snow that can be triggered by the sun, wind, a heavy storm, a change in temperature, and the weight of something on it. Sluff avalanches are caused by loose, light snow beginning to tumble down a mountain, growing larger and larger. Slab avalanches are caused by a large slab of snow being released from its mooring and slips down a mountain slope, and attaches more snow, growing larger.


Most popular Locations:

Avalanches are most popular in the Alpine countries of France, Austria, Switzerland, and Italy. The US is ranked 5th worldwide. Colorado, Utah, and Alaska are most popular.


Why Does it Occur Where it Does?

Ranges with heavy snowfall cause them, so mountainous, snowy areas have them. The amount of sun combined with heavy snowfall influences it as well, which explains why Utah and Colorado often have avalanches.


Local and Global Impacts:

It is a danger to humans; avalanches bury anyone and anything in its path. However, they can benefit animals by the food filled debris they bring down the mountain. Avalanches have a big impact of the local economy. Roads are often shut down because of them, as well as businesses and ski resorts having to close due to them.


Current Technology Used to Predict Avalanches:

3DLM System: This is laser technology mapping now being used to predict avalanches. It monitors snow buildup, and movement, as well as weaknesses in the snow.

SASE: a new system in India, information has not been released yet.

How Effective is the Current Technology?

The technology is almost always accurate. There have only been a few cases where an avalanche has happened without prediction. However, these systems are not everywhere, so not all avalanches can be predicted.


Recent Avalanches:

Sheep Creak, Colorado


6 back country skiers caught, 1 buried

5 buried and killed from a slab avalanche


West Buttress, Denali, Alaska

5 climbers caught, 4 killed from a slab avalanche


Both of these avalanches were predicted, but the victims either ignored it, or they didn't know about it.

Bibliography:

"Avalanche.org - Home Page." Avalanche.org - Home Page. N.p., n.d. Web. 22 Oct. 2013. <http://www.avalanche.org/>.

Fink, Micah. "How Avalanches Form." PBS. PBS, n.d. Web. 22 Oct. 2013. <http://www.pbs.org/wnet/savageplanet/04extremes/01avalanche/indexmid.html>.

"Natural Hazards | Avalanches." Natural Hazards. N.p., n.d. Web. 22 Oct. 2013. <http://www.n-d-a.org/avalanche.php>.

Turtenwald, Kimberly. "Positive & Negative Effects of an Avalanche | EHow." EHow. Demand Media, 01 June 2011. Web. 22 Oct. 2013. <http://www.ehow.com/info_8527959_positive-negative-effects-avalanche.html>.