Information regarding historic avalanches obtained from a survey.

: Information regarding an avalanche observed in the past. Mapped based on a survey of inhabitants of the area where the phenomenon took place. The boundaries shown are based on the explanations given by the witnesses consulted. Information is usually taken from Avalanche Zones close to inhabited areas where avalanches have historically interfered with human activity. For this reason the majority of the information is found around these zones. They are shown in purple. Cartography often maps only the avalanche arrival zone, as the descriptions usually refer to their extent and the damage caused.