While scientists and experts are making progress in detecting and even preventing avalanches, more than 150 people worldwide die annually from them. There is still plenty of information that researchers don’t have about what happens to people during avalanches, as this is something that can’t be studied empirically for reasons that are quite obvious (it wouldn’t be nice to make people get caught in avalanches in order to study what happens).
Most people who get caught by avalanches-thousands each year-manage to escape. However, just because most people escape from avalanches doesn’t mean one has to be less careful about them-some people may escape from avalanches precisely because they have basic survival knowledge that applies in general or to avalanche situations in particular.
Mountain avalanches occur as a result of several factors. In simple terms, avalanches form where there is a mass of snow and a slope for it to slide down. When temperature changes (and note that it doesn’t have to change a lot ), the snow may slide down. Slab avalanches are the most common and deadly types of avalanches and occur when layers of a snowpack slide down the slope. While wind is a relevant factor in slab avalanches, most of these avalanches are caused by the victim.
Sometimes avalanches are caused on purpose with the goal of reducing the risk of hazardous avalanches. In large hazard terrains or those where significant human activity takes place, prevention avalanches are often produced through explosives. As the video suggests, prevention avalanches are pretty and somebody seems to have quite an interesting job.
Several factors can increase the risk of an avalanche: weather, temperature, slope steepness, slope orientation (north or south), wind direction, terrain, vegetation and snowpack conditions. Because some of these conditions can change even hourly, it is important to pay attention to the surroundings during wintertime trekking travel. It’s also worth keeping in mind that deadly avalanches do not have to be big and remarking that there’s only a foot of snow on the ground does not guarantee that an avalanche will not occur.
If you are caught in an avalanche you should:
– Get as light as possible in order to move fast. Let go of ski poles (if you have them) and get out of your pack to make yourself lighter
– Do your best to make “swimming” motions, thrusting upward in order to stay near the surface of the snow as much as possible. Some avalanche survivors also say that rolling like a log helped them move toward the edge of the avalanche. When avalanches come to a stop and debris starts to pile up, the snow can become extremely hard and getting out of it without being on the surface with the hands free is almost impossible.
– If you get caught by the snow and you are near the surface or know where the surface is, you should try to stick an arm or leg in order to make yourself visible for rescuers
– If you are not near the surface, try to maintain an air pocket in front of your face using your hands and arms punching into the snow. Try to remain as calm as possible and do not breath fast to preserve as much air as possible. When the avalanche stops you may have only a few seconds before the snow hardens. As such, creating air space is one of the most important things you should do in this situation. You should take a deep breath to expand your chest and hold it, as otherwise, you may not be able to breathe once the snow hardens
– In order to preserve air, do not yell unless rescuers are close. Because snow is a good insulator, rescuers will often hear you only when they are extremely close to you.
If someone else is caught in an avalanche, you should:
– Try to determine where the victim is being while paying particular attention to the point where you last saw them
– If the avalanche has stopped, wait for two minutes to make sure there is no further danger. If you believe some danger does exist, another member of the group (assuming there is one) must go in a safe location in order to alert if another avalanche starts. If you are alone, it is best to go for help if you don’t see anything that would inform you where the victim is
– Look for clues on the surface of the snow starting with the point where the victim was last Kick over any large chunks of snow in order to find clues. The equipment of the victim may indicate location or at least the direction where the avalanche carried them; mark these spots if you come across them. Be sure that other people don’t leave any items away from the search area, as this could confuse search efforts
– If you find the victim unbury them as quickly as possible and try to attend injuries, shock, and/or hypothermia
– You should mark where the victim was last seen in case you lost the sight of them or there are no visible clues on the surface. Look at the path of the snow and try to figure out where they might have ended up. If you are wearing an avalanche transceiver, switch them to ‘receive’’ and try to locate a signal.
– If you are using probes, start from the place where the victim was last seen or (better) with the area where the victim was buried provided that you are fairly confident you know it. Stand in a straight light across the slope, shoulder to shoulder. Insert the probes repeatedly as you move down slope in a line and pay attention to shallow depressions in the slope and the uphill sides of rocks and trees, as there are terrains traps where the victim may have been buried.
– If searching for clues or using transceivers and/or probes don’t help you find the victim, it is likely time to find outside help.
Hopefully, your status as a happy trekker will remain constant during your exploration sessions and avalanches won’t be something to be concerned with. That being said, it is highly recommended that you remain avalanche-aware. For (significant) more details about avalanches and avalanche survival, I recommend the article published by NSIDC.
National Snow and Ice Data Center: https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5444915.pdf
Popular Science: https://www.popsci.com/caught-in-an-avalanche