Avalanche behavior rules. Actions in case of an avalanche

Avalanche is a rapid, sudden movement of snow and (or) ice down steep mountain slopes, posing a threat to the life and health of people, causing damage to economic facilities and environment. Avalanches form on treeless mountain slopes whose inclination angle is greater than 14°. This is a critical slope at which the snow constantly slides down. An avalanche begins when a layer of freshly fallen snow is 30 cm or when the thickness of old snow is more than 70 cm. The steepness of the slope, most favorable for the formation of an avalanche, is 30-40°.

Avalanche speed can reach from 20 to 100 m/s. Thus, a snow avalanche is a mass of snow falling or sliding from steep mountain slopes and moving at an average speed of 20-30 m/s. The fall of a snow avalanche is accompanied by the formation of a pre-avalanche air wave, which produces the greatest destruction.

Formation of an avalanche layer

Avalanches are possible in all mountainous areas where snow cover is established. Avalanche-prone areas in Russia are the Kola Peninsula, the Urals, North Caucasus, Eastern and Western Siberia, Far East.

The formation of avalanches occurs in an avalanche source, which is a section of the slope and its foot within which the avalanche moves.

Avalanches are caused by prolonged snowfalls, intense snow melting, and explosions during road construction.

After heavy snowfalls in the mountains, there is a threat of avalanches. This is warned using special signs.

The impact force of an avalanche can reach from 5 to 50 tons per square meter. Avalanches can cause the destruction of buildings, engineering structures, and cover roads and mountain trails with snow. Residents of mountain villages, tourists, climbers, geologist and other people who find themselves in the mountains and caught in an avalanche may be injured and find themselves under thick snow.

Protecting the population from the consequences of avalanches

Great importance for protecting the population from the consequences snow avalanches has their prediction. A special surveillance system is in place for this purpose.

Data received from the observation system is processed and presented in the form of forecasts.

Based on the forecasts received, preventive measures are planned and implemented,

In conditions of the threat of avalanches, they organize control over the accumulation of snow in avalanche-prone areas and cause artificial descent of developing avalanches during the period of their least danger.

Protective structures are being built in avalanche-prone areas, rescue equipment is being prepared and rescue operations are being planned. The population is being warned about the danger of avalanches.

Means for preventing avalanches

Rules of conduct for avalanche zones

Let's consider the recommendations of specialists from the Russian Ministry of Emergency Situations, developed for the population living in avalanche zones. Follow the basic rules of behavior in avalanche areas: do not go to the mountains in snowfall and bad weather; when in the mountains, monitor the weather changes; When going out into the mountains, know the places of possible avalanches in the area of ​​your route.

Rules of behavior in avalanche zones: 1 - if there is danger of an avalanche, listen to radio messages; 2 - if you find yourself in the mountains during an avalanche, try to run away from it; 3 - try to hide behind a rock ledge; 4 - once in the snow mass, make “swimming” movements with your hands

Information about avalanches can be found in the search and rescue service of the Russian Ministry of Emergency Situations. And if you are going to be in an avalanche zone, report your intentions (register) to the search and rescue service of the Russian Ministry of Emergency Situations.

Avoid areas where avalanches may occur. They most often descend from slopes steeper than 30°; if the slope is without bushes and trees - with a steepness of more than 20°. With a steepness of more than 45°, avalanches occur with almost every snowfall.

Remember

The most dangerous period for avalanches is spring and summer from 10 a.m. to sunset!

When an avalanche occurs, if there is a decent distance from you to it, you need to quickly walk or run out of the way of the avalanche to a safe place or take cover behind a rock ledge in a recess.

If it is impossible to escape from the avalanche, get rid of all things and take a horizontal position; cover your mouth and nose with a mitten or scarf to prevent suffocation; in the snow, move your arms and legs (pretend swimming) to stay on the surface; try to clear the layer of snow in front of you to make breathing easier.

When the avalanche has stopped, try to move up.

Don’t lose your composure, don’t fall asleep, save your energy, remember that they are looking for you (there are cases when people were rescued from an avalanche on the fifth and even thirteenth day)

Test yourself

1. Where do avalanches form?
2. Name the reasons for avalanches.

After lessons

1. Ask parents or other adults if they were present when the avalanche occurred. Based on their story, prepare a report on the topic “Personal safety during an avalanche.”
2. Write down the main causes of avalanches in your safety diary. Give examples of these phenomena, descriptions of which you have come across in the literature, means mass media. You can use the Internet.

Workshop

You are in a mountainous area where avalanches are possible. What are your actions to maintain personal safety in such a situation?

The vast majority of modern skiers have the word avalanche evokes no more emotion than the assassination of the Prime Minister of Uruguay, for example. As an event, of course, tragic, but very distant, and in no way affects people skiing on weekends on prepared slopes not far from the city limits. Nowadays it is customary to call them skiers, although this type active rest has a very weak, rather morphological and historical, relationship to the mountains themselves.

But outside of public snow attractions, where nothing more dangerous than a concussion or knee injury can happen to a person, everything is different. Mountains, real snowy mountains, are as they were and have remained since the time of their creation - formidable, dangerous, treacherous, but at the same time attractive, beautiful and alluring. And there, in the mountains, snow avalanches are the same reality as public transport in cities.

So this article is intended for those who, having mastered alpine skiing or snowboarding on prepared slopes, strive for greater heights and, accordingly, greater risk. How big is this risk? How justified is he? Does an avalanche always bring only death, or can you escape from it by following a number of rules?

Where do snow avalanches happen?

In general, it is fair to say that snow masses capable of turning into an avalanche can form on any mountain slope from 15 to 45 degrees. On slopes with less steepness, even in the event of an avalanche, the avalanche is not able to gain sufficient power to destroy, and on greater slopes, the snow is simply not able to hold on. However, when special weather conditions arise, for example when snow accumulates, avalanches also form on 50-degree slopes. Such phenomena are especially dangerous, as they have absolutely catastrophic destructive power.

But a mountain slope alone is not enough for the formation of avalanches; a whole series of conditions are also necessary for huge masses of snow not only to accumulate in a certain place, but also to fall down, and then gain speed and kinetic energy under the influence of earth’s gravity.

The first important condition, in addition to the presence of the slope itself and its steepness, is the length of the avalanche run-up, that is, the section of the slope on which a snow wave can not only accelerate, but also carry along new masses of snow. Thus, the well-known formula of kinetic energy, in the form of the product of mass by the square of the speed, divided in half, is fed by the increase of both variables - the speed increases due to the long steep slope, and the mass of the avalanche increases due to the entrainment of tens and hundreds of tons of new snow , sticking to the primary wave with every second. This is what gives an avalanche its colossal destructive power.

To others important conditions For an avalanche, the formation of a sufficient and suitable snow cover is necessary. Its formation often occurs during heavy, prolonged snowfalls. It is known that when the snow cover grows by two centimeters per hour, within ten hours it may occur. avalanche danger.

In the mountains, weather is more important than anywhere else, and, like nowhere else, it brings with it a whole series of dangers that have killed tens of thousands of people. These include unexpected temperature changes, stormy winds accompanied by snowstorms, and the bright sun, burning with ultraviolet radiation and burning out the retina. But in light of avalanche danger, skiers and snowboarders in the mountains should pay special attention to two important weather conditions. This is heavy, prolonged snowfall, especially with strong winds.

The wind crushes snowflakes, creating a layer of fine, very dense snow, significantly different in structure from the underlying layers, which greatly facilitates the process of separating such a layer and its descent down the slope. If snowfall with wind begins after a slight thaw, then fine snow falls on a crust of hard ice crust, and in this case an avalanche becomes virtually inevitable - a gust of wind is enough for it to occur.

Therefore, if the described weather conditions occur, in order to escape from an avalanche, you should refrain from riding in areas of avalanche danger, that is, on slopes with the specified steepness and under them. In fact, this is the only sane way really escape from an avalanche, while all others provide only certain chances for survival. It should be understood that most of the prepared ski slopes are not only located in areas that prevent avalanches, but also, in addition, specialists constantly monitor the condition of the snow cover and, in the event of an avalanche danger, close all or part of the slopes. And while riding ski resort in the Alps, for example, you can be greatly insured against accidents.

But in the absence of prepared trails, or on the Russian trails of the Caucasus, where the local population is only interested in income from them, but not in ensuring safety, as well as on semi-wild slopes in the Khibiny Mountains, you should take care of your own safety.

Khibiny, Kirovsk, due to the special type of relief, generally belong to extremely avalanche-prone places, and therefore skiing there on slopes with a slope above 15 degrees and below them is a kind of “Russian roulette”, when it depends only on chance whether you return home or not.

What types of avalanches are there?

For a long time it was believed that an avalanche is formed from a snowball that rolls down a slope and grows larger due to the adhesion of new snow to it. It is now known that this is not the case, however, and in the age of nanotechnology, the exact physics of the formation and behavior of snow avalanches has not been sufficiently studied due to the need to take into account a number of factors that largely depend on one another. Currently, the hydrometeorological service and special services for the study of avalanches and the prevention of avalanche danger rely mainly on statistical data collected over the entire period of observation of avalanches. That is, the classification is based on an analysis of events that have already occurred and may not take into account any conditions unique to a particular place and time. But such a statistical principle is quite sufficient for preventing avalanches, for declaring avalanche danger and for creating schemes for rescuing people after an avalanche.

In principle, an avalanche is always snow avalanche. IN general view, without taking into account physical subtleties, this is the separation of some part of the snow cover over one or another extent under the influence of various mechanical influences, and then the sliding of this snow mass downward under the influence of gravity. In this case, the primary front of the avalanche becomes a trigger for the sliding of more and more sections of snow cover both before the wave and after its passage, and the shaft itself, due to the mechanical adhesion of snow particles, also gains additional mass.

All types of avalanches known to mankind fall under these criteria, and their classification divides avalanches either by the nature of their path, such as “jumping avalanches,” or by the nature of their occurrence, such as “layer avalanches.”

As a rule, avalanche danger occurs when a snow cover with a thickness of 50 to 70 centimeters forms on slopes with a steepness of 25-50 degrees. But avalanches are known to occur on slopes of 15-20 degrees with a snow cover thickness of only 40 centimeters, and isolated cases have been recorded on slopes of 10 degrees. This indicates little knowledge of the process of avalanche formation itself, as well as the unpredictability of the snow elements.

As a rule, avalanche speeds range from 115 to 180 km/h, but avalanches have been recorded that reach speeds of 500 km/h, which exceeds the landing and take-off speed of a modern fighter jet.

Despite the fact that most often avalanches are not only predicted in a timely manner, but are prevented by artillery shelling or by blowing up avalanche-prone areas, many populated areas in the Alps continue to suffer from avalanches. And even in such a seemingly “childish” place as the Azau Valley, near Elbrus, where nothing like this could possibly happen, an avalanche occurred not so long ago. Although there were no casualties, the avalanche caused material damage.

But Cheget, neighboring Elbrus, on the contrary, is famous for avalanche danger, which is why guns are permanently installed under its slopes, from which the slope is fired when the danger of snow melting exceeds the norm.

Jumping avalanches are considered the most destructive. They occur when an avalanche, while moving, jumps off a cliff and moves through the air for some time, picking up speed catastrophically quickly. The impact of such an avalanche on the ground is comparable in energy to the explosion of a tactical nuclear land mine and leaves colossal impact holes in the ground, sometimes turning into lakes.

Dry avalanches are formed in winter, when severe frosts reign in the mountains. Huge masses of low-density dry snow easily accelerate to 200 km/h and form in front of them a real shock wave of compressed air with a pressure of about 800 kilograms per square meter. Even without reaching buildings, such avalanches are capable of knocking out glass along with fragments of window frames with a shock wave, collapsing layers of plaster and creating cracks in brickwork.

Wet avalanches, occur during the thaw period, when water layers form between layers of snow with different densities. These avalanches rarely reach speeds above 50 km/h, but after stopping they almost instantly harden into ice, which makes it completely impossible to dig them out on their own and greatly complicates the work of professional rescuers.

Snow and ice avalanches-- the least studied and most unpredictable phenomenon. They occur at any time of the day and at any time of the year, while for other avalanches the morning hours are considered relatively safe. The start of such avalanches begins with the calving of a glacier, and is often accompanied by thunderclaps. Then the glacier splits and, jumping from one rocky “shelf” to another, quickly gains colossal speed and becomes the cause of other, now snow avalanches. Snow and ice avalanches crush everything in their path, carrying away stones and ice blocks with a diameter of more than a meter. It is almost impossible to survive if caught in a snow-ice avalanche or a glacier. Such a gathering caused the death of the film crew Sergei Bodrova.

Having the information listed above, a person traveling to the mountains will be able to understand in what conditions an avalanche is more likely and in what conditions it is less likely, that is, he is partially able to independently predict the degree of his own safety. In addition, you should absolutely not ride in areas that are famous for avalanche danger or where there are traces of avalanches, such as fallen trees or huge cones of snow at avalanche stopping points - the so-called avalanche cones.

But in places intended for skiing, the probability of getting caught in an avalanche is much less, but the main thing is that immediately after the disaster strikes, rescuers will begin work, whereas in the wild areas those caught in an avalanche still need to be found.

A snow avalanche is one of the most dangerous natural phenomena, which is typical for mountainous areas. From the name itself it is clear that snow is involved in this process.

Avalanche definition. This is a type of landslide when a large volume of snow and ice slides or falls down steep mountain slopes. The speed depends on the steepness of the slope, the volume and severity of the snow. On average this is 20–30 meters per second.

Avalanche in the mountains

Along the way, the weight of the snow mass increases because it captures new volumes. And the weight of some of them can reach tens, hundreds of tons. In rare cases, not only the snow melts, but also the glacier. Then the weight of the entire mass can reach tens and hundreds of thousands of tons.

Causes

In mountainous areas, especially if these are high peaks, there is almost always snow, including in summer. In winter, the layer of snow cover becomes larger. This increases the load, as a result of which, due to the steepness of the slope, a certain mass begins to roll down, gradually increasing. A snow avalanche is a natural process.

Avalanche: photo

They have always been and will be in mountainous areas. But if people live in these areas, the avalanche becomes dangerous. In the mountains they try to build houses in safe places where avalanches do not reach. Therefore, residential buildings and other structures rarely suffer from such natural phenomena, but such cases sometimes occur.

In most cases, the victims are people who, for one reason or another, ended up in this place. These are athletes involved in alpine skiing, climbers who conquer peaks. There are also risks of avalanches on ski slopes. In these places, avalanches are provoked in advance and artificially using special equipment to ensure safety.

In most cases the cause is natural. But an avalanche can also be triggered by people if they decide to go to the mountains when rescue workers have informed in advance that it is dangerous. Any slightest mechanical impact can be the beginning of snow melting.

The most common causes of avalanches include:

• heavy snowfalls, increasing the volume of snow mass on the slopes
• human factor (mechanical impact, loud sound, shot, etc.)
• an increase in air humidity, which also makes the snow heavier
• earthquakes (mountains are usually located in seismic zones)

According to the nature of movement they are divided into:

• Osovy — go down over the entire surface and look more like a landslide
• Jumping - fall from ledges
• Tray - pass in the form of furrows through rock weathering zones and natural gutters

According to movement they are divided into:

• Streaming
• Cloud
• Complex

How dangerous is an avalanche?

Large snowfalls can destroy entire settlements located at the foot of the mountains. Fortunately, this happens extremely rarely, because people try not to settle in dangerous areas. Mostly people suffer. There is very little chance of survival. The snow mass is very heavy and can immediately break bones, which deprives a person of the chance to get out. And then there is a high risk of remaining disabled, even if he is found and dug out from under the snow.

Even if the bones are intact, snow can clog Airways. Or simply, under a huge layer of snow, a person simply does not have a sufficient supply of oxygen, and he dies from suffocation. Some are lucky, and they manage to be saved. And it’s good if without negative consequences, because many have frostbitten limbs amputated.

Precursors of an avalanche

The main harbinger is weather conditions. Heavy snowfall, rain, wind create hazardous conditions, so it’s better not to go anywhere on this day. You can also take a general look at the general condition of the area. Even small landslides of snow indicate that it is loose and the humidity is high. It's better to play it safe.

The most dangerous period for avalanches is considered to be winter, in the moments after precipitation falls.

If you notice an avalanche 200–300 meters away, there is a small chance of escaping from it. You need to run not down, but to the side. If this was not possible, you must perform the following steps:

• cover your nose and mouth with gloves to prevent snow from getting in there
• clear the snow in front of the face and also in the chest area so that you can breathe normally
• you can’t scream, because it takes energy, and anyway, due to the high sound-absorbing properties of snow, no one will hear anything
• you need to try to get out, trying to remove the snow on the way, compact it
• you should not fall asleep to be alert and give a sign if rescuers are close

How to escape an avalanche

Compliance with these rules increases the chances of survival in such an extreme situation.

Avalanche equipment

Today, many manufacturers of sports and tourism goods offer special avalanche equipment. This includes the following devices and equipment:

• Avalanche sensor- it must be turned on immediately as soon as the athlete goes to the mountains. In the event of an avalanche, other members of the group who managed to escape from it, as well as rescuers, will be able to record the signal from this sensor, quickly find and rescue the person.

• Shovel. It is more needed by those in the group who managed to escape the avalanche in order to dig out those who fell under it.

• Avalanche probe. This device is needed to quickly find a person. With its help, you can determine the exact depth of snow under which a person is located in order to calculate the forces and dig him out.

• Avalung system from Black Diamond- a special device that removes exhaled air to the back. This is necessary so that the exhaled warm air does not form a snow crust in front of the face, completely blocking the access of oxygen.

We talk in more detail about avalanche equipment in our separate article.

Avalanche areas in Russia

Avalanches in Russia are not uncommon. These are the mountainous regions of our country:

• Khibiny on the Kola Peninsula
• Kamchatka
• Caucasus Mountains
• ridges and highlands Magadan region and Yakutia
• Ural Mountains
• Sayan Mountains
• Altai Mountains
• ridges of the Baikal region

The most destructive avalanches in history

Destructive, terrible avalanches are mentioned in many ancient chronicles. In the 19th and 20th centuries, information about avalanches was already more detailed and reliable.

The most famous snow avalanches:

• 1951 Alps (Switzerland, Italy, Austria). This winter there was a whole series of avalanches due to heavy snowfalls and bad weather. 245 people died. Several villages were wiped off the face of the earth, and almost 50,000 people lost contact with the outside world for a long time until rescuers came to their aid.

• 1954 Austria, village Blons. On January 11, 2 avalanches occurred at once, which claimed the lives of several hundred residents. More than 20 people are still missing.

• 1980 France. The avalanche killed about 280 tourists at the ski resort.

• 1910 USA, Washington state. A huge avalanche in an area where there had never been one before hit a railway station and claimed more than 10 lives.

A lot of avalanches occur in Asia: in Pakistan, Nepal, China. But there are no accurate statistics about deaths and destruction.

We also invite you to watch a video of the largest snow avalanches:

Interesting too

Mountains are undoubtedly one of the most beautiful and mesmerizing panoramas on Earth. Many strive to conquer the majestic peaks, not fully realizing how severe such beauty is. That is why, when deciding to take such a courageous step, extreme people face difficulties in all their manifestations.

Mountains represent a rather dangerous and complex terrain, in the vastness of which there is a constant mechanism of gravity, so destroyed rocks move and form plains. Thus, mountains eventually turn into small hills.

There can always be danger in the mountains, so you need to undergo special training and be able to act.

Avalanche detection

Snow avalanches are one of the most devastating and dangerous destructive phenomena of nature.

A snow avalanche is a rapid, sudden, minute-long process of moving snow and ice, occurring under the influence of gravity, the water cycle and many other atmospheric and natural factors. This phenomenon most often occurs in the winter/spring period, much less often in summer/autumn, mainly at high altitudes.

It is always worth remembering that the harbinger of an avalanche is primarily weather conditions. Hiking in the mountains in bad weather: snowfall, rain, strong wind - is quite dangerous.

Most often, a snow avalanche occurs lasting about a minute, while covering a distance of about 200–300 meters. It is extremely rare to be able to hide or run away from an avalanche and only if it has become known at least 200–300 meters away.

The avalanche mechanism consists of the sloping slope, the avalanche body and gravity.

Sloping slope

The level of slope and the roughness of its surface greatly influence the avalanche danger.

A slope of 45–60° usually does not pose a danger, since during snowfalls it is gradually unloaded. Despite this, such places under certain weather conditions can create avalanche accumulations.

Snow will almost always fall from a slope of 60–65°; in addition, this snow can linger on convex areas, creating dangerous blows.

Slope 90° - the collapse is a real snow avalanche.

Avalanche body

Formed from accumulations of snow during an avalanche, it can crumble, roll, fly, or flow. The type of movement directly depends on the roughness of the lower surface, the type of snow accumulation, and swiftness.

The types of avalanches based on the movement of snow accumulations are divided:

• to streaming;
• cloudy;
• complex.

Gravity

Acts on a body on the surface of the Earth, directed vertically downwards, being the main moving force that promotes the movement of snow accumulations along the slope to the foot.

Factors influencing the occurrence of an avalanche:

• type of matter composition - snow, ice, snow+ice;
• connectivity - loose, monolithic, layered;
• density - dense, medium density, low density;
• temperature - low, medium, high;
• thickness - thin layer, medium, thick.

General classification of avalanches

Avalanches of powdery, dry recent snow

Such an avalanche usually occurs during heavy snowfall or immediately after it.

Powder snow is fresh, light, fluffy snow made up of tiny snow flakes and crystals. The strength of snow is determined by the rate of increase in its height, the strength of its connection with the ground or previously fallen snow. It has quite high fluidity, which makes it possible to easily flow around various obstacles. In different cases they can reach speeds of 100–300 km/h.

Avalanches caused by snowstorms

This convergence is the result of snow being transported by a blizzard. Thus, snow is transferred to mountain slopes and negative landforms.

Avalanches of dense dry powder snow

They arise from snow a week or more old, which during this time is compressed and becomes much denser than freshly fallen snow. Such an avalanche moves more slowly, partially turning into a cloud.

Avalanches

They grow after the collapse of snow cornice blocks, which sets them in motion large volume snow.

Dust avalanches

An avalanche is characterized by a huge cloud or a thick coating of snow on trees and rocks. It is created when dry, powdery recent snow melts. The dust avalanche sometimes reaches speeds of 400 km/h. Risk factors are: snow dust, strong shock wave.

Avalanches are layered

They arise through the melting of sheet snow and reach speeds of 200 km/h. Of all snow avalanches, they are the most dangerous.

Avalanches of hard stratified snow

The flow is formed by the descent of solid layers of snow over a weak, loose layer of snow. They consist predominantly of flat snow blocks resulting from the destruction of dense formations.

Soft formation avalanches

A snow flow is formed by the descent of a soft layer of snow along the underlying surface. This type of avalanche is created from wet, settled dense or moderately bound snow.

Avalanches of monolithic ice and ice-snow formations

At the end of winter, snow deposits remain, which under the influence of external factors become much heavier, turning into firn, which eventually turns into ice.

Firn is snow cemented by frozen water. Formed by changes or temperature fluctuations.

Complex avalanches

Consist of several parts:

• flying cloud of dry snow;
• a dense flow of layered, loose snow.

They occur after a thaw or a sharp cold snap, which is the result of snow accumulation and its separation, thereby forming a complex avalanche. This type of avalanche has catastrophic consequences and can destroy a mountain settlement.

Avalanches are wet

They are formed from snow accumulations with the presence of bound water. Occur during the period of accumulation of moisture in snow masses, which occurs during precipitation and thaw.

Avalanches are wet

They arise due to the presence of unbound water in snow accumulations. Appear during a thaw with rain and warm wind. They can also occur by sliding of a wet snow layer over the surface of old snow.

Mudflow-like avalanches

They arise from snow formations with big amount moisture, the moving mass of which floats in a large volume of unbound water. They are the result of long thaws or rains, as a result of which the snow cover has a large excess of water.

The types of avalanches presented are quite dangerous, rapid flows, so you should not think that some are safer than others. Basic safety rules must always be followed.

Avalanche safety

The term avalanche safety refers to a set of actions aimed at protecting and eliminating the tragic consequences of avalanches.

As practice shows, in most accidents, extreme sports enthusiasts themselves are to blame, who, without calculating their own strengths, themselves violate the integrity and stability of the slopes. Unfortunately, fatalities occur every year.

The main rule for safely crossing mountain ranges is complete knowledge of the territory being traversed, with all the dangers and obstacles, so that in an extreme situation you can calmly and carefully leave the dangerous section of the route.

People going to the mountains need to follow basic avalanche safety rules and know how to use avalanche equipment, otherwise the likelihood of getting caught in a snowfall and dying is very high. The main equipment is avalanche shovels, beepers, avalanche probes, a float backpack, maps, and medical equipment.

Before going to the mountains, it will be useful to take courses on rescue work in case of a collapse, first aid, and making the right decisions to save life. Also an important step is mental training and ways to overcome stress. You can learn this in courses to practice techniques for saving people or yourself.

If a person is a beginner, it will be useful to read books about avalanche safety, which describe different situations, moments, and stages of overcoming them. For a greater understanding of avalanches the best option will personal experience, obtained in the mountains in the presence of an experienced teacher.

Avalanche Safety Basics:

• psychological attitude and preparation;
• mandatory visit to the doctor;
• listening to instructions on avalanche safety;
• taking with you a sufficient amount of food, small in volume, a spare pair of clothes, shoes;
• thorough study of the route and upcoming weather conditions;
• taking a first aid kit, flashlight, compass, equipment on a hike;
• going to the mountains with an experienced leader;
• studying information about avalanches in order to have an idea of ​​the degrees of avalanche safety in case of a landslide.

A list of avalanche equipment that you need to be able to work with confidently, quickly, for your own safety and to save victims:

• tools for searching for victims: transmitter, avalanche ball, beeper, radar, avalanche shovel, avalanche probe, other necessary equipment;
• tools for checking snow flooring: saw, thermometer, snow density meter and others;
• tools for rescuing victims: backpacks with inflatable cushions, avalanche breathing apparatus;
• tools for transporting victims, as well as medical equipment: bags, stretchers, backpacks.

Avalanche slopes: precautions

To avoid getting caught in an avalanche or if there is a high probability of an avalanche situation, you need to know a few important rules on avalanche safety and ways of prevention.

• move on safe slopes;
• do not go into the mountains without a compass, know the basics of wind direction;
• move along elevated places, ridges, which are more stable;
• avoid slopes with snow cornices hanging above them;
• return along the same road that they walked forward;
• monitor the top layer of the slope;
• do tests for the strength of snow cover;
• fasten the belay well and reliably on the slope, otherwise an avalanche can drag a person with it;
• take spare batteries for your phone and flashlight on the road, and also have the numbers of all nearby rescue services in your mobile phone’s memory.

If a group or a certain number of people still find themselves under an avalanche, you need to call rescuers, immediately starting the search yourself. In such a situation, the most necessary tools will be an avalanche probe, beeper, and shovel.

Every person who goes to the mountains should have an avalanche probe. This tool performs the function of probing snow during search work. It is a disassembled rod, two to three meters long. During safety courses, a mandatory item is the assembly of an avalanche probe, so that if an extreme situation arises, it can be assembled in the shortest possible time.

An avalanche shovel is indispensable when searching for victims and is necessary for digging out snow. It is more effective when combined with an avalanche probe.

A beeper is a radio transmitter that can be used to track a person covered in snow.

Only with coordinated, quick actions can a comrade be saved. After thorough avalanche safety instruction, a person will be mentally and physically ready to help others.

In conclusion, I would like to emphasize that hiking in the mountains should not be carried out in bad weather, in the evening or at night; when crossing a dangerous area, you must use rope belay, and be sure to have beepers, flashlights, avalanche shovels and avalanche probes in your arsenal. Some of these tools must necessarily be 3–4 m in length.

By observing all the rules and following the instructions, a person will protect himself from harmful consequences and return home safely.

Write to us if the article was useful.

Materials from the website www.snowway.ru and other open sources were used.

Many dangers await climbers, snowboarders and ski lovers. alpine skiing. But the most inexorable and unpredictable of them are avalanches. What are they? Below is a detailed classification of avalanches.

According to Tushinsky

Back in 1949, Professor Georgy Tushinsky proposed a typology of snow avalanches based on differences in the specifics of movement paths.

The geographer divided the types of snow masses descending from the mountains into:

1. Tray. They move along a strictly fixed vector from glacial trenches, as well as from craters formed as a result of the destruction of rocks.
2. Basics. When a gap forms in a layer of snow and part of the mass slides down a flat slope, on which there are no erosion cuts or furrows.
3. Jumping. On the path of the site there are steep cliffs from which snow slides into free fall.

By the nature of movement and structure of mass

A dust avalanche is formed from dry snow. During the movement, the structure of the mass is destroyed and creates a cloud of snow dust. The speed of snow avalanches of this type can reach 250 km/h. It is the most dangerous and destructive.

The same classification of avalanches established the presence of so-called “snow slabs”. They are formed from a layer of fine-grained dry snow with a density of up to 400 kg per cubic meter, under which there is a less dense snow mass. Hollow areas form under the slabs, which destroy the top layer and provoke its subsidence.

When the imbalance reaches a critical point, a stepped separation line is formed, perpendicular to the surface of the mass, and a collapse occurs over a large area, the speed of which can reach 200 km/h.

There is also an “avalanche from a point”. It is formed from wet snow in the form of a huge drop coming off a rocky outcrop. This occurs due to the heating of the rocks, as a result of which the lower layer of the mass is fed with moisture, becomes heavier and begins to shift. Most snow avalanches of this type can be observed in spring. Their speed does not exceed 120 km/h.

In the summer season, hydraulic avalanches often occur, in which masses move that resemble mudflows in composition: they contain a mixture of stones, water, soil and snow.

Due to the occurrence

Based on this criterion, in 1984 V. Akkuratova proposed the following typology:

• Blizzard avalanches

They are formed from the redistribution of the upper layer due to the transfer of masses during a snowstorm. Wind-blown accumulations of snow grains are deposited in relief depressions. The rate of formation of a snowstorm layer depends on the structure of the relief, as well as on the speed of the snowstorm.

• Advection

They are formed as a result of water seeping into a layer of snow, which causes its structure to be destroyed and the lower layer to thaw and the connections between dense clusters of snowflakes to break.

• Avalanches of dry “young” snow

During intense snowfall, a fresh layer is formed on the surface of the mass, consisting of crystals with a density of no more than 200 kg per 1 cubic meter.

The stability of this structure depends on the strength of adhesion, as well as on the area of ​​contact with the “old” layer and on the rate of accumulation of dry crystals.

• Avalanches caused by metamorphism

Due to the deformation of the structure of ice particles and the connections between them, snow recrystallization occurs, as a result of which loosened layers appear in the upper cover. This leads to an avalanche.

• Insolation

Snow absorbs solar energy, under the influence of which it begins to move. The movement speed is relatively low.

• Mixed

The movement of snow masses occurs due to an increase in air temperature with the simultaneous accumulation of solar energy in the snow.

• Avalanches triggered by snow compression

They are formed as a result of overvoltages arising from an increase in the density of snow masses caused by a strong decrease in air temperature.

Classifications by strength and level of danger

Based on the volume and approximate weight of the moving layer, avalanches can be divided into five types:

1. A disaster capable of destroying a populated area or having a destructive impact on a vast area of ​​forest (more than 4,000 km²);
2. Sliding of minor accumulations of snow that are not capable of causing harm to humans;
3. An avalanche that can destroy a forest area of ​​up to 4,000 km², as well as damage buildings, vehicles and equipment;
4. A slight shift in the snow mass that can harm a person;
5. A medium-sized avalanche capable of breaking trees and damaging cars and buildings.

If we talk directly about the danger of an avalanche for humans, then it is usually assessed on a 5-point scale:

The danger is negligible. There is a minimal chance of snow melting, but in general the surface is dense and stable. The conditions are quite reliable for holding events.

The formation of an avalanche is possible only in critical areas of the relief, subject to additional pressure on the slope by the movement of several athletes along it. In quiet areas, you can load slopes with a steepness of up to 50 degrees. It is advisable not to lay routes through problem areas with an inclination angle of more than 45 degrees.

Medium level of danger. At some points on the slope there is a decrease in density and slight destabilization. On steep terrain there is an increased risk of an avalanche. Spontaneous shift of snow masses is unlikely.

Events are permitted if the organizers take into account the structure of the terrain and the specific conditions at the sites. It is allowed to strain normal slopes with an angle of up to 40 degrees. In areas with problematic terrain, loads at an angle of up to 35 degrees are permissible.

Increased danger. On most slopes, the snow masses are unstable and have a loose structure. The probability of an avalanche is high. The most dangerous points are steep slopes. Spontaneous avalanches of medium strength and single falls of large volumes of snow are expected. Events are allowed, but only if their participants are only experienced athletes who have sufficient knowledge of avalanche science, are familiar with the geography of the region, and do not plan to go to high-risk areas. Groups of athletes are prohibited on most routes. The permissible load is on slopes forming an angle of up to 35° in normal areas and up to 30° in dangerous areas.

The snow cover is not compacted and unstable in the vast majority of areas. The probability of an avalanche is high even with a slight load on the slope surface. Movement of groups of athletes is prohibited. Only single events are allowed.

Only professional athletes who are well acquainted with the geography of the area, have impeccable knowledge of avalanche science and good intuition, and are ready to return to base at the slightest suspicion, are allowed to enter the route. Loading in normal and potentially hazardous areas is permitted on slopes up to 25° and 20°, respectively.

Catastrophic danger. Snow masses are mobile and unpredictable. Events are strictly prohibited. Large volume avalanches are occurring on all slopes, regardless of the degree of inclination.