Every winter sports enthusiast knows that skiing – just like every sports – can bear risks. One of those risks is the danger of avalanches. Although relatively few people incur avalanches, the white masses of snow can get life-threatening quickly. The greatest danger with avalanches is to underestimate them and not to be prepared accordingly.
A lesson in avalanches: what are avalanches and how do they develop?
An avalanche is a mass of snow and ice that “rolls down” a mountain at high speed. It can be life-threatening for humans and animals.
Avalanches develop when there is a very high difference in the temperature in the air and the temperature on the ground. This dissolves the crystals in the snow and makes snowflakes melt into an unstable mess.
In these conditions, even small movements on the snow cover can cause masses of snow to come loose and roll down the mountain at high speed and great force.
Types of avalanches
There are various types of avalanches, while most avalanches are a mixture of the following:
Loose snow avalanche
They form at a point where the snow is very loose. Compared to snow slab avalanches (see below), they have less snow mass and a lower speed.
Snow slab avalanche
Snow slab avalanches are bigger and faster (up to 100 km/h) than loose snow avalanches and carry along bigger snow masses, as a whole slab of snow starts skidding.
A flow avalanche is also called wet snow avalanche. It occurs spontaneously and is usually caused by the melting of the snow cover at warmer temperatures. This is why it is an acute danger especially in spring.
This is often triggered when a lot of fresh snow falls, especially on slopes with an inclination of more than 40 degrees. The loose snow and the high air content in fresh snow form a large pressure wave of snow and air.
Causes of avalanches
The development of an avalanche is influenced by many different factors. Some of those are, among others, temperature, wind, type of terrain, amount of snow and the nature of the snow layer. There are both natural causes and external influence that are responsible for avalanches.
One of the most frequent natural causes is loosely lying fresh snow. It increases the danger of snow slipping and, with a lot of wind, can increase the danger of avalanches. Warm temperatures, which make the snow melt, can also trigger avalanches. This is why the risk of avalanches in the mountains is very high especially in spring. Furthermore, steep mountains with declines of 30 percent or more favour avalanches, as the snow masses there are not slowed down by flat plains.
Most avalanches, however, are not induced by natural causes, but 90 percent are caused by external factors. In addition to avalanche blasting (controlled and preventive), “external influences” mainly means animals and people, whose movements on the mountain set the masses of snow in motion.
Especially the trend of deep-snow skiing outside avalanche-protected pistes means that more winter sports enthusiasts are in potential avalanche danger areas. In Switzerland, for example, an average of six winter sports enthusiasts per year are injured by avalanches on off-pistes because they go off-road despite avalanche warnings.
The best protection from avalanches: good preparation & respecting area closures
If you do not plan on skiing off the regular, prepared pistes, you do not need to worry: The controlled pistes are protected from avalanches and are blocked anyway if there is any risk of avalanches. But those who are drawn to the off-piste areas should always go out with necessary respect for potential dangers and prepare themselves adequately.
Because when an avalanche rolls down, it happens at a breath-taking speed. Depending on the situation, avalanches can reach speeds up to 200 km/h. This leaves you with very little time to think and you have to react immediately. So if you want to ski off-piste, you should train the right behaviour in special avalanche preparation courses. Even if you ski in open terrain every winter, it does not hurt to refresh the courses’ contents regularly.
Good preparation is the best protection when you are off-piste. In addition to the avalanche preparation course, this includes the appropriate equipment and checking the weather and avalanche situation report before going into the open ski area. This is important not only because the correct equipment and avalanche behaviour can save lives, but also because you don’t endanger yourself unnecessarily when skiing off-piste. The German Alpine Association offers a good overview of avalanche reports for all alpine skiing areas.
The avalanche report contains important information
The avalanche report contains important information, not only, but especially for those winter sports enthusiasts who want to ski in unprepared and uncontrolled deep-snow areas. Part of the report are, among other aspects, the recent risk levels according to the European avalanche danger scale.
The scales should not be assessed carelessly. Half of the fatal avalanche accidents take place at risk level 3, because many winter sports enthusiasts dare accessing uncontrolled areas despite the increased danger and underestimate the risk.
Apart from the avalanche danger scale, the avalanche report also contains information about the type and the stability of the snow cover, the current weather conditions as well as danger zones that should be avoided. However, one should always keep in mind that the report is no guarantee for safety. It is only a prognosis, as there can be fast and spontaneous weather changes in the mountains. On controlled pistes, the ski area’s operators make sure nobody skis in dangerous weather, indicate danger and, if necessary, close down the lifts. In uncontrolled off-piste areas, each winter sport enthusiast is responsible for their own safety.
Avalanche emergency equipment for off-piste skiers
This is exactly why it is important for off-piste skiers to bring along the right equipment. This includes, for a start, functioning ski equipment, which should meet the current standards, as well as special avalanche emergency equipment.
The emergency equipment includes an avalanche transceiver for rough location, a probe for accurate location of those buried by an avalanche, as well as a carbon avalanche shovel in order to dig out persons who have been buried. Furthermore, an avalanche backpack with airbag can save lives, because the additional volume means that you cannot be buried so quickly by rolling snow masses.
Some winter sports enthusiasts also take a so called avalanche ball when they enter off-piste areas. The ball marks the point where one sinks in to the avalanche, which makes it easier for helpers to find avalanche victims. There also is respiration help for being buried by an avalanche, the so called “Avalung”.
It is important to check the equipment for functionality before departure. Furthermore, every skier must know how to use it.
Reasons why an avalanche is so dangerous
The equipment already shows the two biggest dangers in an avalanche accident beside the risk of injury: Suffocation and freezing to death.
Once you are hit by an avalanche, snow covers your mouth and nose so that you cannot breathe. Furthermore, the mass of snow makes you unable to move. Even if you are not fully covered by snow, this can quickly lead to hypothermia and eventually freezing to death.
This is why it is crucial to find buried skiers as soon as possible. As soon as a person is hit by an avalanche, every second counts. If someone is buried for longer than 15 minutes, it becomes very critical. If a person is partially buried, it becomes dangerous from 30 minutes due to severe hypothermia.
Therefore you should never ski in off-piste areas on your own – if you are buried without any company, which means without any help, you barely have a chance. Small groups, at best led by a mountain guide, are a basic condition for skiing in open terrain. It is important that members of the group keep an appropriate distance from each other. In the event of an avalanche, not all members are hit (simultaneously).
The right behaviour in an avalanche
In case you do happen to get hit by an avalanche, the right behaviour can save lives.
1) Before the avalanche
The right behaviour starts once the avalanche starts rolling. Ideally, you go down to the valley as quickly as possible. However, this only works when you are not too far off in the open terrain, act fast enough and are a very good skier. In fact, time in most cases it is hardly possible to reach the valley in. If you cannot escape to the valley, it is best to first try and get out of the way of the avalanche to the side. If being hit by the avalanche is inevitable, you should throw away ski poles and everything that could hinder or injure you as fast and as far away as possible. Additionally, you should go straight to the side while keeping a straight position on the skis or snowboard. Like this, you will not be hit frontally by the entire weight of the snow masses.
2) During the avalanche
If you have an airbag backpack, you should open it immediately when noticing the danger of an avalanche – it is better to open it once too much than once too little. After that it is crucial to try to keep to the surface. This gives you the best chances not to suffocate and to be dug out faster. In order to achieve this, you best move as if you were crawling. As soon as the avalanche loses speed, crouch down and hold your hands over mouth and nose as air protection. Like this you avoid snow getting into your mouth and nose and ensure access to oxygen.
3) After the avalanche
If you lose orientation in the cold white of the avalanche, it is advisable to spit into the snow. Gravity pulls the liquid down, so it is easier to orientate oneself. However it is better to conserve your strength, as every effort consumes precious oxygen. This is not the case when you hear rescue workers above you. Experts advise you to make yourself heard by shouting loudly so that you can be found and dug up as quickly as possible.
How to help others in an avalanche accident
If it is not yourself but someone from your group who is buried, it is important to act quickly and calmly – time for avalanche victims is short. If you are safe, you should not wait for rescue workers, but intervene yourself.
1) Understand the current situation
First you observe and assess the present situation and try to find out as soon as possible where the person is buried. Then you mark both the point where the person was caught by the avalanche, as well as the point where they disappeared. This makes the actual location easier, as well as the excavation. During the rescue you should always keep in mind your own safety. Rescuers have to protect themselves and those who are buried from following avalanches. This is why you should think about the best and safest escape route after the rescue.
The most experienced person in the group takes command in order to be able to help as calmly and organised as possible, but also as quickly as possible. This includes collecting information:
- How many of the group have been buried?
- What type of avalanche was it?
- How can you call for help?
Of course, all of this has to be done in the shortest time possible, which is why the most experienced member of the group should take over the coordination.
2) Inducing location
As soon as the external conditions are clear, you activate the avalanche transceiver for rough locating. For that, the device has to be switched to receive mode. For the best reception you hold it horizontally and choose the widest range. Then you follow the loudest signals. It is advisable to switch off smartphones and mobile phones so as not to disturb the radio signal. For precise locating you finally use the probe. In case you do not carry any location devices, immediately alarm mountain rescue workers by mobile phone while searching. If you do not have the number saved to your phone, you can call 112 as long as you are in the European Alps – in all European countries you are automatically connected to the emergency service. If you are lucky, you can also try calling the person that was buried and follow the ringtone.
As soon as you found the person that was buried, you start digging them out. The shovels should not be used from above, but from the side, so that you do not shovel more snow onto the person. Then it is necessary to guarantee the person can breathe. Free mouth and nose from snow and, if necessary, protect the face from further snowfall. After that you check heartbeat, breathing and consciousness and, if required, initiate appropriate first aid measures, such as mouth-to-mouth ventilation. These functions should be checked at regular intervals.
4) Secure heat supply
Once the person that has been buried is freed from snow, it is all about securing heat supply. In an avalanche, the body temperature drops by an average of three degrees per hour. As soon as the person has been dug out, the temperature even drops by six degrees per hour.
It is also important the person does not move under their own power in the event of hypothermia, as otherwise they risk salvage death. This occurs when the blood flows from the colder extremities into the warmer centre of the body, i.e. towards the heart. This lowers the overall body temperature and, in the worst case, leads to a heart attack.
5) Bring the person to safety
Once the buried person is stable, they should be brought to safety as soon as possible. This could be the valley, the nearest mountain hut or a hospital.
Caution as top priority
This safety protocol in a descent of an avalanche, can save lives, both when you have been buried yourself but also in order to rescue others. Nevertheless, this does not mean that you can think yourself safe or should carelessly enter dangerous areas. Avalanches are always a threat to life – even if you are only partially buried.
In Germany, the German Alpine Association states in its annual accident statistics that the emergency helpers had to rescue a total of 86 alpine winter sports enthusiasts in the 2016/17 season. Around seven of these emergencies were caused by avalanches. Two people died. This means that two thirds of the causes of death in winter sports are caused by avalanches.
In the same season the alpine police in Austria listed 101 avalanche accidents, in which 17 people died. This means that avalanche deaths account for about 6 percent of all deaths in mountain sports.
In Switzerland, seven people died as a result of avalanches in the 2016/17 season. On average, 25 people die each year in winter sports in Switzerland. This puts the proportion of avalanche deaths at 28 percent.
Even though this does not seem much in absolute numbers, and you do not have to panic about winter sports, it is important to take the danger of avalanches seriously. Studies show: It is mainly the excessively risky behaviour of winter sports enthusiasts that leads to accidents.
If you ski outside of controlled pistes, you are always exposed to potential natural hazards. One of the most threatening dangers is avalanches. Anyone skiing outside the marked, protected and controlled pistes in the ski area must bear in mind that the danger of avalanches is always a danger to life!
This should not keep anybody from off-piste skiing, nevertheless you should only ever enter off-piste areas with the necessary respect for avalanches. This always includes good preparation, functioning safety equipment, avalanche safety training and, above all, a high level of risk awareness. The safest skiers are those who avoid dangers of avalanches.
The most important questions about avalanches
What are avalanches?
An avalanche is a mass of snow and ice that rolls down a steep mountain. Avalanches are often called “white danger” because they are so dangerous.
How do avalanches develop?
Avalanches develop when the snow does not stick firmly to the ground, but becomes an instable layer instead. They are caused by various natural factors such as temperature, wind or type of snow. However, it is mainly external influences such as animals and humans that cause about 90 % of all avalanches.
Why are avalanches so dangerous?
Avalanches develop immensely fast speeds so that you have no time to react. They hit persons within seconds, and the masses of snow can lead to injuries, as well as mainly suffocation and frostbite.
What is part of the emergency equipment?
The standard avalanche emergency equipment contains an avalanche transceiver, a probe and a carbon shovel. Airbag-backpacks or avalanche balls can a helpful part of the safety equipment.
Why should you take part in avalanche training?
In the event of an avalanche, it is all about rescuing people quickly – seconds can be crucial. Those who have learned how to act in an avalanche course act faster, more calmly and more safely, and can thus save the lives of others. It is advisable to refresh the knowledge from the courses regularly.
What is the most important thing to do when you get hit by an avalanche?
The deeper you are buried in the snow, the harder you get to air and the longer it takes to dig you out. This is why the top priority is to keep yourself at the surface as well as possible by making swimming movements.
How can I get air under the avalanche?
It is recommended to form a funnel in front of your mouth and nose with both hands in order to get more oxygen. This also prevents snow from falling into your mouth and nose. Those who are buried should remain as calm as possible and do not make great efforts, so as not to lose valuable oxygen and strength.
How do you help when somebody was buried by an avalanche?
Helpers should always keep calm, inform mountain rescue and, first and foremost, locate the person that was buried. What helps to achieve this is the most precise observation possible and the location devices of the safety equipment. Afterwards, you excavate the buried person, check their vital functions and keep the person warm before you bring them to safety as quickly as possible.