Last week 63 year old High Mountain Guide Jean-Louis Lechène based in Cauterets in the Pyrenees set out from Lys on a ski tour. His objective, the west ridge of the Monné where he continued his climb on crampons. During his climb he spotted a long aluminium tube embedded in the snow. He immediately recognized it as a charge fired from a compressed air avalanche canon. The charge would normally explode with the aim of triggering any avalanche above the resort’s ski pistes before they are opened.
Avalancheur in action - http://www.zapiks.fr/l-avalancheur.html