Hello.
Any number of disturbances, including loud noise or a skier's motion, can cause an avalanche. Even pollution in the Northeast can find its way to Europe, hitching a ride with prevailing winds and causing avalanches in the Alps. That's because snowpack conditions affect the likelihood of avalanches. Soot warms snow and ice faster, creating melt and weakening snow layers, which promulgates avalanches.
Have a nice day
