Avalanches occur when an unstable snowpack collapses, often accompanied by a loud noise. A technical term for whumpfing, this audible sign of an avalanche can be a warning sign, as can shooting cracks or big changes in weather.
Triggers
Avalanches are caused by a number of factors, including loud noises. While loud noises do not have the force of a gunshot, their energy can be enough to trigger avalanches when the sounds are close to the surface. Similarly, even a slight wind can cause an avalanche to occur. An explosion, helicopter, or other loud sound can also cause an avalanche to occur.
Wind
You’ve probably heard about the sonic booms produced by jet planes. But can they cause avalanches? One study found that 20 jet planes could trigger only two avalanches over a seven-day period, a tiny amount of energy that’s not enough to cause a landslide. Yet, the Bond movie On Her Majesty’s Secret Service used 150 kilograms of explosives to trigger an avalanche.
Rain
Avalanches are triggered by a variety of loud sounds and movements in the landscape. A gunshot, charge in the snow, or even a voice in the mountains can cause the snow to move in a certain way and trigger an avalanche. These sounds can trigger a massive avalanche because they send minute vibrations through the snow.
Warming temperatures
Warming temperatures are one of the most prominent contributors to increasing avalanche risks. The Intergovernmental Panel on Climate Change has found that global temperatures are warming, and the American Meteorological Society published their State of the Climate report in 2017. While the rates of warming are uncertain, the impacts of increasing temperatures on avalanche hazard analysis deserve careful consideration. As such, reliable avalanche hazard estimates are essential when designing engineering structures to protect against avalanches.
Earthquake
Avalanches are large masses of snow that come down a mountainside and destroy everything in its path. While they do not often kill people, there have been many recorded incidents, and there have been more than 100 fatalities. These avalanches most often happen in ski areas and on mountains where people go hiking. In areas where avalanches are frequent, authorities carefully monitor the snowpack and advise skiers to avoid the area. A loud noise can trigger an avalanche.
Squeaking sand
A new study aims to explain the acoustic emission from tumbling sand. The study, led by Tom Patitsas, a theoretical physicist at Laurentian University in Sudbury, Ontario, suggests that the sound of tumbling sand is caused by intergranular friction. The sound is generated when sliding sands rub against similar-sized grains underneath the avalanche. These grains may be arranged in chain-like patterns, which intensify the sound. The resulting amplitude of the vibration will be very large.
People’s weight
A large amount of avalanche deaths are caused by people’s weight. In fact, nearly 90 percent of all avalanche deaths involve the victim or their party. A typical slab avalanche can travel 80 miles per hour, and since 1950, 235 people have died in slab avalanches in the U.S.
Recent avalanches
Recent avalanches often build on top of each other and involve several slides. These avalanches are sometimes caused by a loud sound, such as a loud whistle or a loud crack. In some cases, these slides can even be triggered by snow that has fallen naturally from trees. In any case, it’s important to avoid the area where an avalanche may have been triggered and stay safe.
Visual clues
If you are in an area where there are frequent avalanches, you should look out for signs of an avalanche. Buildings that have fallen victim to an avalanche will look unfinished and have broken windows and doors. Often, avalanches can be started by loud sounds. For example, a loud crack or bang on a rock can set off an avalanche. A loud roar can also trigger an avalanche.
