Types of avalanches

The types of avalanches are defined by few criteria: if they are from dry or wet snow, if the snow is loose or agglutinate, if they are falling till the hard ground or one layer is slipping on another. Based on that criteria there can be defined four types of avalanches: loose- from dry snow, slush- from snow saturated by water, slab avalanches- from wet and dry snow.

The avalanches from dry loose snow are falling in cold weather, usually after snowing. They break off from one point and get larger bit by bit. Other name of this type of avalanches is powder snow avalanches. They are moving with increasing speed and on longer slopes the destructive capability is increasing from the pushed air in front of them. Their speed can reach 300 km/h.

Slush avalanches occur usually when the weather is getting warmer. Then the level of humidity increases as well as the weigh of the snowpack. They move slowly and usually occur at the same places.

Slab avalanches occur when there is a stiff layer of snow that slips on a loose lower layer. They are usually formed when snow is deposited by the wind. The slab starts moving as an indiscrete mass and under the effect of the speed and its weight could form blocks.

Slabs from wet snow also slip but the reason is the melting of the base. Usually they are slower and heavier than the slabs from dry snow but also have huge destructive capability. When moving down they form blocks very often.