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Page 3
Another avalanche type is the cornice avalanche. A cornice is a mass of snow stretching out from a ridge or cliff line, often superbly sculptured like a frozen water wave, usually formed when snow blown by prevailing winds from slopes on one side of the ridge are deposited in the lee. At times, cornices seem to defy gravity as they hang suspended in space. Though they are often very dense and hard surfaced, they maintain an extremely fragile hold on the mountain. When a cornice loses its precarious hold, it can trigger surrounding snowfields to avalanche as it moves downslope. Deadly cornice avalanches are often triggered by skiers, hikers, or snowmobilers underestimating the cornice's fragility as they pass over or under the hanging cornice.
Each year, avalanches claim more than 150 lives worldwide, but that number has increased over the past few decades as more people travel to backcountry mountainous regions for recreation. In the past decade, avalanches in Canada have claimed an average of 13 lives per year, but at least 28 died in avalanches during the 2002-03 winter season. The United States recorded 229 avalanche deaths between 1995 and 2002, with 35 during 2001-02. [Portions of this article were adapted from material in The BC Weather Book: From the Sunshine Coast to Storm Mountain by Keith C. Heidorn © 2004. Copyright 2005, Keith C. Heidorn, All Rights Reserved. (Illustrations, unless otherwise specified, ©Keith C. Heidorn, All Rights Reserved.)]
The copyright of the article Avalanche! - Page 3 in Meteorology is owned by . Permission to republish Avalanche! - Page 3 in print or online must be granted by the author in writing.
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