AVALANCHE

Subject : Geography

Context : BRO worker dies trapped in snow as avalanche hits Zoji La in Ladakh

Concept :

Avalanche is a rapid downslope movement of a large detached mass of snow, ice, and associated debris such as rocks and vegetation.
Small avalanches, or Sluffs, occur in large numbers, while large avalanches that may encompass slopes a kilometer or more in length with millions of tons of snow, occur infrequently but cause most of the damage.
Humans have been exposed to the threat of sliding snow for as long as they have inhabited mountainous regions.

Types of Avalanches:

Loose snow avalanches-formed in snow with little internal cohesion among individual snow crystals.
Slab avalanches-Originate in snow with sufficient internal cohesion to enable a snow layer, or layers, to react mechanically as a single entity.
Wet snow avalanches-These move more slowly than dry ones and are seldom accompanied by dust clouds.
Direct action avalanches –These are the immediate result of a single snowstorm. They usually involve only fresh snow.
Climax avalanches-Result of a series of snowstorms or a culmination of weather influences. Their fall is not necessarily associated with a current storm or weather situation.