Artificial Release of Avalanches in North America^∗

Abstract

Approximately 10⁵ explosive charges are used annually in North America to release avalanches artificially. High-speed explosives (5000 to 8000 m s^–1) such as pentolite and blasting gelatin are preferred. One kilogram of high explosive is generally considered adequate; however, many avalanche workers use larger charges (10 kg). The appropriate size of charge for a given set of conditions remains a matter of speculation. Military artillery is effective on remote slopes, although shrapnel and noise are objectionable, and the cost of nonsurplus ammunition is restrictively high. Several alternate systems are under study.