Initiation of an avalanche by an explosive.

Credit: SLt M.X. Dery/Canadian Forces/Handout via Reuters

Explosive triggers are commonly used for avalanche mitigation and snowpack testing by ski areas, highway departments, railways, and mines. While there are many ways to initiate avalanches with explosives, delivery methods generally consist of either hand placement or remote placement. For example, small, hand-delivered explosives (2-3 lbs) are commonly used to reduce the avalanche risk at ski areas. It is also common for mitigation teams to utilize artillery and/or remote avalanche control systems (RACS) to create avalanches in start zones that are difficult to access, or more dangerous to workers.

Small hand shots (typically 2 or 3 pounds of explosive) delivered onto the snow surface have a larger impact than a skier or rider, but a smaller impact than larger or suspended explosives. Credit: Associated Press

This Gasex system delivers a propane/oxygen explosion just above the snow surface. It is self-contained, remotely detonated, and can be fired every two minutes as fuel allows. Credit: Natural Hazards Control Solutions

Helicopters are commonly used to deploy explosives to hard-to-reach start zones. Credit: Washington State Department of Transportation

A blasting cableway or “bomb tram” suspends charges above the snow surface for a larger impact, as well as allows patrollers to deliver a charge to terrain that is difficult to access. Credit: Wyssen