An avalanche is a rapid flow of snow down a slope. In mountainous areas, avalanches are among the most serious threats to life and property due to their destructive capability resulting from their potential to carry rapidly an enormous mass of snow over large distances.
They can be triggered by either natural phenomena or by human activity (e.g. deforestation, winter sports). Avalanches can also be classified in particular according to:
The cause: natural or human;
The snow quality: humid or dry;
How slippery it is: over a previous snow surface or with that previous snow surface.
Prepared by AFEM - European Natural Disasters Training Centre (Ankara, Turkey) & the Editorial Board