The formation and development of avalanches

The formation and development of avalanches can be divided into three sections, namely, formation zone, passage zone and accumulation zone.

An avalanche mostly forms in the upper part of the mountain, where the snow is rich and thick. For example, the high snow waves, gradient that exceed 50 to 60 degrees, the lower end of the glacier, etc, are the formation areas of avalanches.

Passage zone of avalanche is under the formation zone, which is often a straight u-shaped groove from top to bottom. Because avalanches often pass through, despite being covered with snow, the groove is still very smooth, without big ups and downs or obstacles and its length can reach up to several hundred meters and width, 20 ~ 30 meters but it is not too wide, or the snows that slide down are not very concentrated, which cannot form an avalanche.

Accumulation zone is immediately below the passage zone, which is the place that snow slide body stops due to the moderate slope foot. Looking from the morphology, it seems like a pyramid. So it is also called avalanche cone or avalanche heap.