Avalanches can be triggered either naturally or artificially. Natural triggers include heavy snowfall, rapid depositing of snow by wind, a rapid rise in temperature, fall of a cornice, ice fall, or earthquake. 

Artificial triggers include skiers, snowboarders, snowshoers, snowmobiles, hikers, machinery, and explosives. 

An avalanche is said to be triggered remotely when the trigger initiates the avalanche from a distance.