home Diets and weight loss Conditions for the occurrence of snow avalanches. Causes of snow avalanches The main causes of snow avalanches

Conditions for the occurrence of snow avalanches. Causes of snow avalanches The main causes of snow avalanches

Called a tiger in the skin of a lamb by an innocent, at first glance, White snow Matthias Zdarsky is an Austrian researcher who studied the question of what an avalanche is. Softly falling snow fascinates even those who don’t like winter - it’s too beautiful a picture, like a fairy tale. And the crystal stars smoothly falling to the ground create a deceptive impression of fragility and defenseless tenderness. However, excessively active snowfalls are fraught with danger, and a serious one. After all, not only snowdrifts, but also avalanches can grow from small snowflakes. So what is an avalanche? The definition of this concept is given below. And now a little history.

A brief excursion into history

In all likelihood, an avalanche is a phenomenon that exists as long as the steep slopes of mountains, and Polybius mentions the first large-scale snowfalls, causing the death of hundreds of people, in the context of the history of the campaign of the Carthaginian army through the Alps. And in general, this mountain range, beloved by tourists and climbers, has a long history of disasters behind it. It is not for nothing that in the 20th century, in some areas, masses were celebrated in memory of those killed under snow rubble, because in this case an avalanche means pain and grief for the relatives and friends of those who suffered from it. It is also noteworthy that in one of the last winters of the First World War, more soldiers died from this on the Austro-Italian front than directly during hostilities. And December 16, 1916 went down in history as “Black Thursday,” when six thousand people were missing in one day. Hemingway, who was in the Alps during the same time period and described his definition of what an avalanche means, noted that winter landslides are terrible, sudden and bring with them instant death.

Residents of Norway, Iceland, Bulgaria, the United States, the Russian Federation, Canada, as well as Asian countries: Turkey, Nepal, Iran, Afghanistan also suffered from the “white death”, and in the latter, by and large, no records of the dead are kept. Tens of thousands of lives and counting snow avalanches, fell from Mount Huascaran in Peru.

What is an avalanche? Etymology of the word

The ancient Romans called this phenomenon a “pile of snow.” Each nation had its own definition. What does avalanche mean? This is a beautiful, exciting and dangerous natural phenomenon. The very meaning of the word “avalanche” is also interesting, the origins of which are the Latin root lab, meaning “instability”, although it came into the Russian language through German, since in ancient German there was a definition of Lavine. Xuan Zang poetically called them “white dragons,” and in Pushkin’s time avalanches were called landslides. In the Alps and the Caucasus, the names of individual mountains, gorges and valleys are already “speaking”. For example, Lansky Forest or Zeygalan Khokh (“the mountain from which avalanches always come down”). Sometimes the ability to read onomastics, although it won’t tell you everything about snow debris, can protect you from unforeseen circumstances.

What is an avalanche

An avalanche is a type of landslide, a significant mass of snow that moves or even falls from the slopes of mountains under the influence of gravity. It simultaneously creates an air wave, which accounts for a significant part of the destruction and damage that is almost inevitable in this natural disaster.

Having started its movement, the avalanche can no longer stop, falling lower and lower and capturing accompanying stones, ice blocks, branches and uprooted trees on its way, turning from seething white snow into a dirty mass, vaguely reminiscent of a mudflow. The flow can continue its “fascinating journey” until it stops in flat areas or at the bottom of the valley.

Factors influencing the descent of snow masses from the mountains

The reasons that cause avalanches largely depend on the old snow - its height and density, the condition of the surface underneath it, as well as on the increase in new masses of precipitation. The intensity of snowfall, subsidence and compaction of the cover, and air temperature also influence. In addition, a fairly long open slope (100-500 m) is optimal for the start of an avalanche path.

It is not for nothing that the main “architect” of this natural phenomenon is called the wind, since an increase of 10-15 cm is enough for the snow to melt. Temperature is also one of the most important factors that can provoke a disaster. Moreover, if at zero degrees the instability of the snow, although it arises quickly, passes no less actively (it either melts or an avalanche occurs). And when the low temperature is stable, the avalanche period increases.

Seismic vibrations can also activate snow melting, which is not uncommon in mountainous areas. In some cases, jet flights over dangerous zones are enough.

In general, the increasing frequency of snow avalanches is indirectly or directly related to stormy economic activity a person who is not always reasonable. For example, those cut down today forested areas They used to serve as a natural protection against snow slides.

Periodicity

Depending on the frequency of occurrence, a distinction is made between intra-annual convergence (for the winter and spring periods) and average long-term convergence, which includes, respectively, the overall frequency of avalanche formation. There are also systematic avalanches (annually or every 2-3 years) and sporadic ones, which occur at most twice per century, which makes them especially unpredictable.

Movement, source of natural phenomenon

The nature of the movement of snow masses and the structure of the source determine the following classification: flume snow avalanches, special and jumping. In the case of the former, the snow moves either along a tray or along a specific channel. Special avalanches cover the entire accessible area of the terrain while moving. But with the jumping ones it’s already more interesting - they are degenerated from the flume, appearing in places where the drainage is uneven. The snow mass has to “bounce”, as it were, to overcome certain areas. The latter type is capable of developing the highest speed, therefore the danger is very significant.

Snow is treacherous and may well creep up unnoticed and silently, falling with an unexpected shock wave, destroying everything in its path. The peculiarities of the movement of these natural masses underlie another division into types. It distinguishes a layer avalanche - this is when the movement occurs tangent to the surface of the snow located below, as well as a ground avalanche - it slides directly along the ground.

Scale

Depending on the damage caused, avalanches are usually divided into especially dangerous (they are also spontaneous) - the volume of material losses amazes the imagination with their scale, and simply dangerous - they complicate the activities of various organizations and jeopardize the peaceful, measured life of populated areas.

Properties of snow

It is also important to note the classification associated with the properties of the snow itself, which is the basis of the avalanche. There are dry, wet and wet. The former are characterized by a high speed of convergence and a powerful destructive air wave, and the masses themselves are formed at sufficiently low temperatures ah after significant snowfalls. A wet avalanche is snow that has decided to leave its cozy slopes at temperatures above zero. The speed of movement here is lower than in the previous ones, however, the density of the cover is greater. In addition, the base can freeze, turning into a hard and dangerous layer. For wet avalanches, the raw material is viscous, wet snow, and the mass of each cubic meter is about 400-600 kg, and the movement speed is 10-20 m/sec.

Volumes

Well, the simplest division is small and almost harmless, medium and dangerous to humans, as well as large ones, which in their path wipe out buildings and trees from the face of the earth, and turn vehicles into a pile of scrap metal.

Is it possible to predict the occurrence of avalanches?

It is extremely difficult to predict avalanches with a high degree of probability, since snow is an element of nature, which, by and large, is practically unpredictable. Of course, there are maps of dangerous areas and both passive and active methods are being taken to prevent this phenomenon. However, the causes and consequences of avalanches can be different and very noticeable. Passive methods include special shield barriers, forest areas, and observation points for dangerous areas. Active actions consist of shelling areas of possible landslides from artillery and mortar installations in order to provoke the convergence of snow masses in small batches.

Snow avalanches sliding down the mountains in any of the options represent no matter how small or large they are. It is extremely important to take into account all the factors influencing the occurrence of snow masses and their movement along an uncertain route to unknown goals, so as not to sacrifice too expensive gifts to the elements.

All about avalanches: interesting facts

The avalanche speed can reach 100-300 km/h. A powerful air wave instantly turns houses into ruins, crushes rocks, demolishes cable cars, uproots trees and destroys all life around.
Avalanches can come from any mountain. The main thing is that they are covered with snow. If there have been no avalanches in a certain area for 100 years, then there is always the possibility that they may occur at any time.
Approximately 40 thousand to 80 thousand people lost their lives during the First World War, they were buried under avalanches in the Alps. Data is approximate.
In America (California), people surrounded Mount St. Gabriel with deep ditches. Their dimensions are equal to football fields. Avalanches descending from the mountain linger in these ditches and do not roll into populated areas.
This destructive natural phenomenon is called differently among different peoples. The Austrians use the word "schneelaanen", which means "snow flow", the Italians say "valanga", the French - "avalanche". We call this phenomenon an avalanche.

When snow accumulates on steep slopes in mountainous areas, it can pose a serious danger to humans. Large masses of snow falling from a slope form snow slides, or avalanches, which have great destructive power. They can destroy entire villages on their way. Therefore, in the Alps, avalanches are called “white doom” or “white death”.

At first glance, it seems strange that light snow like feathers can bring so much trouble. But it should be remembered that one cubic meter of water weighs a ton, and a cubic meter of compacted, compacted snow weighs about 300-400 kg. There are avalanches weighing up to 200, and sometimes 500 thousand tons. Falling from a height of one or two kilometers, the avalanche strikes with enormous force. In addition, when an avalanche falls, a large air wave is formed destructive force. If measures are not taken in a timely manner, an avalanche can become a natural disaster.

Such a disaster occurred during the construction of a railway in the Alps. Near the tunnel, where the work was carried out, as usual, a village with service buildings arose, residential buildings for builders and a two-story hotel built on a solid concrete foundation.

The engineers who built the railway did not consider it necessary to first examine the mountain slopes, although local residents warned of the impending danger of a snowfall. After some time, noticing ominous signs of an avalanche, local residents advised the builders to immediately leave the village and seek refuge in neighboring villages located under reliable cover.

However, construction managers did not heed this sound advice. On the evening of the day of the disaster, people gathered at the hotel. Chuckling, they read a warning letter sent by someone from the valley. But not even an hour had passed since an avalanche fell from the slope of a neighboring mountain. It was too late to save ourselves. Although the avalanche stopped a few meters from the hotel, the air wave that preceded it destroyed the house. The roof of the building was thrown onto the slope of another mountain. The heavy billiard table was later found in a mountain river.

The people sitting facing the mountain were suffocated by the terrible air pressure. Of the 30 people in the hotel, 12 were killed and the rest were wounded.

If avalanche snow reaches a building, then at the site of the collapsed avalanche only the rough surface of the snow masses and fragments of the building remain.

REASONS FOR AVALANCHES

At first glance, the avalanche seems completely unexpected. In fact, this does not happen by accident. Soviet avalanche researchers clarified previous ideas and found out a lot of new things about the causes of this natural phenomenon.

What causes the occurrence and fall of avalanches?

While temperatures drop to -10° and -20° in the upper layers of the snow cover, temperatures close to 0° (about -2°) remain in the layers of snow adjacent to the ground.

Thus, in a snow cover even 40-50 cm thick, a difference in temperature arises between the upper layers of snow and the layers located at earth's surface. As a result of this temperature difference, the movement of water vapor and evaporation of snow begins in the lower layers of snow. Gradually, the lower layer of snow loosens, loses stability and turns into an avalanche layer.

Skiers are very familiar with the sudden settling of snow with a characteristic whooping sound. This phenomenon is explained by the loosening of the lower layers of the snow cover (formation of an avalanche layer); it occurs not only on the slopes of the mountains, but also on the plains. But these conditions are not yet sufficient for the formation of an avalanche. Avalanches only occur if snow accumulation occurs on steep slopes (15° and above), where the snow cannot be retained. Particularly dangerous are slopes with a steepness of 30-35°, on which snow slowly accumulates until its thickness reaches a significant thickness. Then the snow mass rolls down.

An avalanche also occurs when the slopes are overloaded with snow during snowstorms or within two days after the end of the snowfall and during thaws. Avalanches carry a lot of rock fragments and form large mounded landforms in mountain valleys. Snow avalanches are a characteristic natural phenomenon in mountainous and polar regions of the globe.

COMBATING AVALANCHES

Scientists, studying avalanches in areas where power plants, industrial and residential buildings, railways and highways are being built, have learned to predict the time and place of avalanches, and have also developed protective structures. Avalanche-prone slopes are built up with snow-retaining walls, guide dams and avalanche cutters. Reinforced concrete avalanche galleries are being built over mountain roads. One of effective ways Avalanche control, which is used in the Caucasus and the Khibiny Mountains, is mortar fire on avalanche-prone slopes. This method makes it possible to artificially cause avalanches to fall. small sizes, gradually unloading large accumulations of snow from avalanche-prone mountain slopes.

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Avalanches form when there is sufficient snow accumulation and on treeless slopes with a steepness of 15 to 50°. At a slope of more than 50°, the snow simply falls off, and conditions for the formation of a snow mass do not arise. Optimal situations for avalanches occur on snow-covered slopes with a steepness of 30 to 40°. There, avalanches occur when the layer of freshly fallen snow reaches 30 cm, and old (stay) snow requires a cover of 70 cm thick. It is believed that a smooth grassy slope with a steepness of more than 20° is avalanche dangerous if the snow height on it exceeds 30 cm. With increasing slope steepness the likelihood of avalanches increases. Shrub vegetation is not an obstacle to the gathering. Best condition for the snow mass to begin to move and gain a certain speed, the length of the open slope is from 100 to 500 m. Much depends on the intensity of the snowfall. If 0.5 m of snow falls in 2-3 days, then this usually does not cause concern, but if the same amount falls in 10-12 hours, then snowfall is quite possible. In most cases, the snowfall intensity of 2-3 cm/h is close to critical.

Wind also plays a significant role. So, in a strong wind, an increase of 10 - 15 cm is enough, and an avalanche can already occur. The average critical wind speed is approximately 7-8 m/s.

One of the most important factors influencing the formation of avalanches is temperature. In winter at relatively warm weather When the temperature is close to zero, the instability of the snow cover increases greatly, but quickly passes (either avalanches occur or the snow settles). As temperatures drop, periods of avalanche danger become longer. In spring, with warming, the likelihood of wet avalanches increases. The lethality varies. An avalanche of 10 m3 already poses a danger to humans and light equipment. Large ones are capable of destroying capital engineering structures and forming difficult or insurmountable blockages on transport routes.

Speed is one of the main characteristics of a moving avalanche. In some cases it can reach 100 m/s. The ejection range is important for assessing the possibility of hitting objects located in avalanche zones. A distinction is made between the maximum emission range and the most probable, or long-term average.

The most probable ejection range is determined directly on the ground. It is assessed if it is necessary to place structures in the avalanche zone for a long period. It coincides with the boundary of the avalanche fan. The frequency of avalanches is an important temporal characteristic of avalanche activity. A distinction is made between average long-term and intra-annual recurrence rates. The first is defined as the frequency of avalanches on average over a long-term period. Intra-annual frequency is the frequency of avalanches during the winter and spring periods. In some areas, avalanches can occur 15-20 times a year.

The density of avalanche snow is one of the most important physical parameters, which determines the impact force of the snow mass, the labor costs for clearing it, or the ability to move on it. For dry snow avalanches it is 200 - 400 kg/m 3 for wet snow - 300 - 800 kg/m 3.

An important parameter, especially when organizing and conducting emergency rescue operations, is the height of the avalanche flow, most often reaching 10 - 15 m.

The potential period of avalanche formation is the time interval between the first and last avalanches. This characteristic must be taken into account when planning the mode of human activity in a dangerous area. avalanche snow destructive natural

It is also necessary to know the number and area of avalanche foci, the start and end dates of the avalanche period. These parameters are different in each region. In Russia most often such natural disasters occur in the Kola Peninsula, the Urals, the North Caucasus, in the south of Western and Eastern Siberia, Far East. Avalanches on Sakhalin have their own characteristics. There they cover everything altitude zones- from sea level to mountain peaks. Descending from a height of 100 - 800 m, they cause frequent interruptions in train traffic on the Yuzhno-Sakhalinsk Railway. In the vast majority of mountainous regions, avalanches occur annually, and sometimes several times a year. How are they classified?

To assess the probability of avalanches of freshly fallen and blizzard snow, 10 main avalanche-forming factors are used (Engineering Geology..., 2013).

1. Height of old snow. Snow first fills the unevenness on the slope, and only after that can a flat, smooth surface emerge, allowing new layers of snow to slide down. Therefore, the greater the height of old snow before the snowfall begins, the greater the likelihood of avalanches.

2. The condition of old snow and its surface. The nature of the snow surface affects the adhesion of chewed snow to old snow. The smooth surface of wind-driven snow slabs or ice crust favor avalanches. The presence of layers and interlayers of deep frost is especially predisposing to avalanche formation. A rough surface, wind-driven sastrugi, and spongy rain crusts, on the contrary, reduce the possibility of avalanche formation.

3. The height of freshly fallen snow or snow deposited by a blizzard. An increase in the depth of snow cover is one of the most important factors in avalanche formation. The amount of snowfall is often used as an indicator of potential avalanche danger.

4. The sight of freshly fallen snow. Dropdown type solid precipitation affects the mechanical properties of the snow cover and its adhesion to old snow. Thus, when prismatic and needle-shaped crystals or star-shaped crystals fall out in frosty, windless weather, a loose snow cover is formed, characterized by low adhesion. The greatest likelihood of avalanches occurs when a cover of freshly fallen fluffy and dry fine-grained snow is formed.

5. Density of freshly fallen snow. The greatest likelihood of avalanches is observed when a snow cover of low density is formed - less than 100 kg/m3. Increasing the density of snow reduces the likelihood of avalanches, but this rule does not apply to snow slabs formed during snowstorms.

6. Snowfall intensity (snow deposition rate). At low snowfall intensity, a decrease in the stability index of snow cover on a slope as a result of an increase in shear forces is compensated by an increase in stability due to an increase in adhesion and the coefficient of friction during snow compaction. As the rate of snow deposition increases, the influence of an increase in its mass prevails over the influence of its compaction, and creates conditions for a decrease in the stability of the snow cover and the formation of avalanches.

7. The amount and intensity of precipitation is a factor characterizing the increase in snow mass per unit area of the horizontal projection of the slope, including taking into account liquid precipitation and snowstorms.

8. Snow settling. The process of compaction and settling of falling snow increases its adhesion and the coefficient of internal friction and thereby contributes to increasing the stability of the snow cover.

9. Wind. Wind transfer leads to redistribution of snow cover, the formation of hard crusts, snow slabs and blows. The wind forms snow cornices and below them - accumulations of loose snow. A strong wind creates air suction from the snow layer, which contributes to the migration of water vapor and loosening of the lower layers of snow. Wind plays an important role in avalanche formation processes, especially as a factor in blizzard snow transfer.

10. Temperature. The influence of temperature on avalanche formation is multifaceted. Air temperature affects the type of solid precipitation particles that fall, the formation, compaction and temperature regime of snow cover. The difference in the temperature of the snow cover in depth is also determined by the processes of temperature-gradient metamorphism. A rapid decrease in air temperature can lead to the formation of temperature cracks in the rupture of the snow layer and the occurrence of avalanches.

To active methods of avalanche protection include measures aimed at initiating avalanches so that the consequences are minimal. Shooting from guns has long been used for these purposes. artillery piece(both with a projectile - in the area where a dangerous snow mass is located, and with a blank shot, in order to create an acoustic impact leading to a deliberate avalanche). Methods of simply “trimming” snow masses with skis and collapsing snow peaks have long been used, but these methods require good skills and are very dangerous. The most modern way preventing the negative consequences of avalanches - active dynamic avalanche protection, which is a device located in areas of greatest avalanche formation and controlled remotely, which allow influencing snow masses for the purpose of artificially triggering an avalanche, using compressed air or explosions of a gas-air mixture.

Passive avalanche protection measures are aimed at holding snow on the slope and preventing avalanches or at directing avalanches in a safe direction. Such measures include the construction of avalanche barriers, chutes, avalanche cutters and dams on the slopes (Sadakov, 2009). On linear objects, such as roads or railways, avalanche protection galleries are built.

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FEDERAL STATE BUDGET EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

"Tula State Pedagogical University named after. L.N. Tolstoy"

(Federal State Budgetary Educational Institution of Higher Professional Education "Tashkent State Pedagogical University named after L.N. Tolstoy)

Speciality:“Pedagogical education with two profiles of training (mathematics, physics)”

Department: “Algebra, mathematical analysis and geometry"

By discipline:

"Life Safety"

on the topic: “Snow avalanche”

Completed by: st.gr. 120951(1A)

Afanasyeva T.M.

Head of work: Snegirev A.V.

Introduction

Concept and causes of avalanches

Consequences

Human actions during an avalanche

Prevention of dangerous situations

Providing first aid to an avalanche victim

Conclusion

Bibliography

Introduction

Snow avalanches are one of the natural natural phenomena, capable of causing death and causing significant damage. Among other dangers, avalanches are distinguished by the fact that their collapse can be caused by human activity.

Reckless use of natural resources in mountainous regions (deforestation on slopes, placement of objects in open avalanche-prone areas), access by people to snow-covered slopes, and shaking of the snow column from equipment lead to increased avalanche activity and are accompanied by casualties and material damage.

The problem of snow avalanches is most pressing in places where ski resorts and tourism, for example Switzerland, Kamchatka, the Pyrenees, Finland and others.

For my essay, I took the topic “snow avalanche” because this emergency situation is little studied in school or even not touched upon at all. Life is full of surprises and I could very well end up in such a situation, so I want to know how to behave and what to do.

· Study what avalanches are and what are the causes of their occurrence

· Find out what the consequences of an avalanche are

· Review the plan for dealing with this emergency.

· Find out how you can avoid this situation

· Find out what assistance needs to be provided to victims

Concept and causes

An avalanche is the rapid descent of snow cover from a mountain slope under the influence of gravity. Falling snow masses carry melt water, soil, and vegetation with them, but snow always predominates in an avalanche.

Avalanches are possible in all mountainous areas where snow cover is established. The possibility of avalanches is determined by the presence of a favorable combination of avalanche-forming factors, as well as slopes of steepness from 200 to 500 with a snow cover thickness of at least 30-50 cm.

Avalanche-forming factors include: snow cover height; snow density; snowfall intensity; snow cover subsidence; temperature regime of air and snow cover; snowstorm distribution of snow cover.

The most important factors are the increase in freshly fallen snow, the intensity of snowfall and blowing snow transport. In the absence of precipitation, melting may be a consequence of intensive snow melting under the influence of heat, solar radiation and the process of recrystallization, leading to the destruction of the snow layer.

The formation of avalanches occurs in the avalanche source, that is, in the area of the slope and its foot, within which the avalanche moves.

An avalanche source is usually characterized by three zones:

Origin zone (avalanche collection);

Transit zone (tray);

Stopping zone (cone) of an avalanche.

Avalanche classification

Avalanche type	Peculiarities
Tray	Movement along a fixed channel
Slopovaya	Separation and movement along the entire surface of the slopes
Jumping	Free fall from slope ledges
Reservoir	Movement along the surface of the underlying layer of snow
Unpaved	Movement on the ground surface
	Dry snow in an avalanche source
	Wet snow in an avalanche source

Up to 70% of avalanches are caused by snowfall. These avalanches occur during snowfalls or within 1-2 days after they stop.

Avalanches are classified according to their frequency (recurrence):

Systematic, go every year or once every 2-3 years;

Sporadic, disappear 1-2 times every 100 years or less, the location of the disappearance is difficult to determine.

In some areas, systematic avalanches can occur 15-20 times during winter and spring.

Heavy snowfalls, as well as earthquakes of magnitude 5-6 or more, are the causes of the formation of catastrophic avalanches.

Causes of snow avalanches

1. Good heavy snowfall at a speed of 2 cm/hour

2. Rain or prolonged thaw

3. Sudden temperature changes

4. Active solar radiation

5. Disturbance of the crust in the lower part of the slope - loose snow.

6. Strong wind

7. Powerful sound or mechanical impact

Consequences

Due to its suddenness, speed, and enormous destructive power, an avalanche destroys houses on its path, knocks down forests, power lines, roads, bridges, and kills all living things.

A person caught in an avalanche, in most cases, dies from suffocation. In the first moments when a person falls into an avalanche, he is mixed with snow, which clogs his nose and mouth, making it impossible to breathe. Being in the thickness of the snow, when breathing, an ice crust forms around a person, which prevents the passage of air. Except suffocation, man.

Anyone caught in an avalanche can freeze, break arms, legs, spine, get a head injury or a concussion. Just imagine: a huge snow mass of several hundred tons rushes down the mountain at a speed of 150-350 km/h, crushing everything in its path - stones, trees, people.

Human actions

· If the avalanche breaks high enough, quickly step or run out of the way of the avalanche into safe place or take cover behind a rock ledge, in a recess (you cannot hide behind young trees).

· If it is impossible to escape from an avalanche, free yourself from things, take a horizontal position, tucking your knees to your stomach and orienting your body in the direction of movement of the avalanche.

· Cover your nose and mouth with a mitten, scarf, collar; When moving in an avalanche, use swimming movements of your hands to try to stay on the surface of the avalanche, moving towards the edge where the speed is lower.

· When the avalanche has stopped, try to create space near your face and chest, it will help you breathe.

· If possible, move towards the top (the top can be determined using saliva, allowing it to flow out of the mouth).

· If you find yourself in an avalanche, do not scream - the snow completely absorbs sounds, and screams and meaningless movements only deprive you of strength, oxygen and warmth. You can stuff your mouth with a gag.

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

If your companion is caught in an avalanche

· 1. Try to trace the path of its movement in the avalanche. After it stops, if there is no danger of repeated avalanches, start looking for a friend down from the place where you saw him in last time. As a rule, the victim lies between the point of disappearance and the location of the lightest items of his equipment.

· 2. Having found a victim, first of all free his Head and chest from snow, clear his airways, and then provide him with first aid before medical care.

· 3. If within half an hour it was not possible to find the victim on your own, you must call a rescue squad.

HOW TO ACT AFTER AN AVALANCHE

· If you find yourself outside the avalanche zone, report the incident by any means to the administration of the nearest populated area and begin searching and rescuing the victims.

· After getting out from under the snow on your own or with the help of rescuers, inspect your body and, if necessary, provide yourself with help. When you reach the nearest populated area, report the incident to the local administration. Go to a health center or doctor, even if you think you are healthy. Next, act as directed by the doctor or rescue team leader.

· Inform your family and friends about your condition and whereabouts.

How to look for people under an avalanche?

Survival under an avalanche of people depends on how effectively your comrades search for them. Panic and confusion at such a moment can cost the lives of those trapped in the snow. So, how to properly look for a person under an avalanche?

· The location of the victim is often indicated by his belongings (backpack, tent, etc.) thrown onto the surface of the snow cover. In addition, a special avalanche tape attached to personal equipment can be a real salvation in such cases.

· If neither things nor avalanche tape could be found, you should visually determine the places where the victim is likely to be buried. Most often these are natural barriers, avalanche curves, trees, rocks, etc. At the same time, it is important to remember where the person was at the time of the avalanche and find out where the snow flow could have transported him, based on its direction and strength.

· You can search for people under an avalanche using a radio (if you have one). Speed probing, which has been tested for centuries - the introduction of probes (long sticks) can also be quite effective. The probes should be used carefully, slowly, without sudden movements. To increase sensitivity, it is better to take off your gloves and immerse the probe in the snow with one hand. It is advisable to probe the area with a chain, with an interval of 1 meter between rescuers. When such a chain moves forward, the probe should be immersed every 70 cm.

Prevention of dangerous situations

Signs of an avalanche zone

1. Avalanches rarely occur on slopes with a steepness of less than 25°.

2. Avalanches sometimes occur on slopes with a steepness of 25 to 35°, especially when this is facilitated by the cutting action of skis.

3. The most dangerous slopes are steeper than 35°. In such places, avalanches are likely with every heavy snowfall.

4. Steep, narrow ravines are natural avalanche routes.

5. Forest ridges, especially those tapering upward, can be avalanche routes.

6. Avalanches rarely occur in dense forests.

7. Slopes with isolated trees are no safer than completely treeless ones.

8. Leeward slopes are favorable for the accumulation of excess amounts of loose snow and the formation of snow boards. The protrusion of the snow cornice is directed towards the leeward slope. The snowdrifts are elongated perpendicular to the direction of the wind, with the leeward slope being steeper.

9. In ravines located perpendicular to the wind, the accumulation of loose snow or the formation of snow boards occurs mainly on the leeward slope.

10. On windward slopes, the snow cover is usually strongly compacted by the wind and is safe.

11. Slopes facing south are favorable for the formation of wet avalanches in the spring and avalanches from fresh snow under the influence of sunlight.

Follow the basic rules of behavior in avalanche areas:

· do not go to the mountains in snowfall and bad weather;

· while in the mountains, monitor the weather changes;

· when going out into the mountains, be aware of possible avalanche sites in the area of your path or walk.

Avoidavalanchedangersbythe followingmeasures:

1. Choose your route carefully. Research known avalanche paths, prevailing winds, and recent snowstorm data. A good source of information is your nearest avalanche guide or ski patrol leader.

2. Avoid known dangerous slopes. Cross a questionable slope one person at a time and as high up the slope as possible or as far away from the possible avalanche site. It is safe to follow the ridge crest, but do not walk on the ledge of the cornice.

3. Be careful. As you move, constantly monitor the snow conditions. Before going out on a big slope, test a small one with the same steepness and orientation in relation to the sun. If you see an avalanche trail from a snow board, know that a similar avalanche may be waiting for you nearby. Watch your shadow. When it is directed towards a slope, the exposure to the sun is greatest. Seek protection in dense forest, on windward slopes and behind natural barriers. Watch the weather: any sudden change is dangerous.

4. Use your time wisely. Wait out a strong storm and for some time after it, until the avalanches disappear or until the snow settles. Control your every step. In the very first hours of the storm, movement is possible. Use this time to exit the avalanche area. In spring, the period between ten o'clock in the morning and sunset is the most dangerous for avalanches. The early morning hours before sunrise are safest.

5. Use self-defense. If you still need to cross a very dangerous place, have one person on skis check the slope. This person must be secured with a climbing rope and avalanche cord. Don't be satisfied with just one check.

Typical avalanche hazards weather

· A large number of snow that fell in a short period of time

· Heavy rain

Significant wind transfer of snow

· The long cold and clear period that followed intense precipitation or a snowstorm

· Snowfalls are initially cold, then warm or vice versa

Rapid rise in temperature (around or above 0°C) after a long cold period

Long periods (more than 24 hours) with temperatures close to 0°C

· Intense solar radiation

Preventing a dangerous situation

The rate of change of snow cover is measured using meteorological instruments or using stationary avalanche rails, installed vertically in areas of avalanche danger and allowing one to monitor the level of snow cover on potentially dangerous slopes from a great distance. If, as a result of observations, it is determined that the level of snow cover reaches a critical level, dangerous slopes are fired from special weapons in order to artificially provoke small avalanches and prevent a global avalanche, which can lead to destruction and human casualties.

Protection of the population from avalanches can also be passive. With passive protection, avalanche slopes are avoided or barrier shields are placed on them. In order to protect against avalanches, forest belts are planted along the roads and protective shields are installed.

First aid

In the event that a person is discovered under the snow in one way or another, it is important to very quickly extract him to the surface. To do this, you need to start intensive digging, using both shovels and improvised tools - metal sheets, etc. However, intensive digging must be careful at the same time, because there is always a risk of causing serious injury to a person with a shovel or something else.

When rescuing a victim from an avalanche, the first thing you need to do is free his mouth and nose to breathe. Moreover, if breathing and heartbeat are no longer observed, it is important to immediately apply cardiopulmonary resuscitation - mouth-to-mouth artificial respiration. While one person carries out resuscitation efforts, others should continue to dig out.

A victim removed from an avalanche without signs of life or with a weak pulse should be tried to be brought back to life with the help of a heart massage, without stopping artificial respiration. At the same time, regardless of the person’s condition, he must be placed in a tent, warmed with warm clothes and heating pads (including those improvised from plastic bags).

A rescued person who is conscious (or after consciousness returns to him) should be given a hot drink (coffee, tea, broth, milk, etc.). Any tonic will be useful. The simplest of them is caffeine, which can be taken along with coffee, in the form of tablets or an injection.

The victim can be transported or moved from place to place only after he has resumed normal cardiac activity and breathing.

Conclusion

This work examined avalanches, the causes of their occurrence and the consequences of their descent, and also provided measures taken by people to protect themselves, the rules of behavior of a person caught in this emergency situation and the provision of first aid to victims. As a result, we can conclude that most often the causes of an avalanche are natural, such as heavy snowfall or a sharp change in temperature. To avoid getting into such a situation, you should take precautions and try not to go into avalanche-prone areas, and also know how to behave if you do end up in an avalanche.

snow avalanche help victim

Literature

1. Bozhinsky A.N., Losev K.S. Basics of avalanche science. - L.: Gidrometeoizdat, 2009. 280 p.

2. Gvozdetsky N. A. Mountains. - M.: Mysl, 2007. 400 p.

3. Geography of avalanches. - M.: Moscow State University Publishing House, 2006, 334 p.

4. Dolgushin L.D., Glaciers. - M.: Mysl, 2006. 448 p.

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