Avalanche mortars are designed by engineers to prevent natural disasters by triggering small avalanches before enough snow builds up to cause a catastrophic avalanche. An avalanche mortar is an explosive projectile that is launched at a slope where an avalanche is likely to occur. The explosion shakes the snow loose from the slope, causing a small avalanche. (Photo above shows an avalauncher, which is used to launch an avalanche mortar. The typical launch method is compressed nitrogen.) Explosives can also be dropped by skiers. The advantage of the avalanche mortar is that it can easily cover a large area and is safer for ski patrollers so they do not have to ski into dangerous avalanche zones to place explosives. The problem with avalanche mortars is that they are susceptible to wind and a dud mortar leaves a live explosive on the mountain. Without the avalanche mortar, snow levels could build to a point at which a huge avalanche could cause casualties and damage structures.