Avalanche: How to Avoid?

Probably the most terrifying phenomenon within mountaineers. A phenomenon that kills skiers, climbers and mountain tourists every year. A phenomenon that occurs suddenly and lasts a few minutes. A phenomenon that is very difficult to predict. In one word – an avalanche.

Any movement of snow mass down the hill or a mountainside, at a speed of more than 1 m/s, is considered an avalanche. According to statistics, most avalanches, which involve humans, occur precisely by their fault. That is why it is very important to have at least minimal knowledge about an avalanche, its types and causes, to master the basic safety rules and know how to conduct rescue operations.

How does an avalanche occur?

The snow layer remains on the slope due to the friction. When the weight of the snow mass begins to prevail over the friction force, an avalanche occurs. Avalanche is usually accompanied by a strong wave of air that destroys everything in front of it.

The snow cover is never uniform. It has different layers, each of which has been formed over a certain period of time. Each layer has its own quality characteristics. A new layer is formed due to snow or wind that pushes the snow layer from one part to another.

Together with all this mass, the pressure in the snow layers increases and because of certain influences, if one of the layers weakens, the force of gravity prevails over the friction force of the snow layers, the layer separates and glides down, taking with it all the snow mass above it.

There are a number of effects that can “provoke” an avalanche.

• Fresh snow increases the pressure on the snow cover and contributes to an increase of the tension in it. It is believed that if more than 30 cm of snow falls during the day, then the risk of an avalanche significantly increases. Not only the amount of snow that has fallen is important, but also its speed. The situation is considered critical if 1.5-2 cm of snow falls in an hour.
• The wind is capable of moving large amounts of snow. The faster the wind speed, the more snow it can move. Sometimes the wind accompanies the snow and drives all the snow mass that has fallen and collects it at one point, significantly increasing the tension in this area, which, in the end, leads to an avalanche.
• Air temperature can affect snow in different ways. In such cases, there are five main scenarios that can develop:

1. A sudden increase in temperature (crossing the zero mark) – dramatically increases the risk of an avalanche.
2. Slow temperature increase without crossing the zero mark – stabilizes the snow cover.
3. Gradual warming during the day and cooling in the evening – a stable weather that maintains snow cover at peace.
4. Cooling – suspends the situation that was before, and gradually makes it worse; the risk of an avalanche increases.
5. Prolonged cold weather increases the tension in the snow cover.

• Solar radiation, in general, has a stabilizing effect on the snow cover. Especially in winter, when the air temperature is always below zero, solar radiation has a softening effect on the frozen layers of snow. But closer to spring, when the air temperature rises above zero, the effect of the sun can change sharply to negative and in a matter of minutes disturb the balance of the snow cover.
• Rain in high mountain areas is extremely dangerous in terms of avalanches. Firstly, the rain itself increases the weight of the entire snow mass. In addition, raindrops penetrate deep into the snow cover, destroying the crystal structure of snowflakes and creating an unstable state for the entire snow cover. In such cases, there is a high probability that all snow mass, down to the ground, will fall and rush down.
• The terrain also affects avalanches. The knowledge of the terrain and the competent planning of the route are a guarantee of a safe ascent. Slopes and inclines are considered influencing factors.

*On different sides of the horizon, the risk of an avalanche under equal conditions can be different. It depends on the effects of the sun and winds. As a rule, in the northern hemisphere, the southern slopes are most dangerous in winter and the northern ones in summer. However, this rule may have a number of exceptions, depending on the particular mountain, snow level and weather conditions.

*Board-shaped ice avalanches mainly occur on slopes with 35-60 degrees of declivity. However, most avalanches occur at an incline of 35 to 40 degrees, reaching their peak at 38 degrees. This slope provides all the conditions for a layer of snow to accumulate, but at the same time remain unstable. With a smaller declivity, the tension is small. On steeper spoles, the snow does not have time to accumulate, and from time to time, there are small avalanches that do not cause much damage.

• The surface of the earth also plays an important role. Usually snow remains worse on flat rocky or grassy slopes. Because of this, the entire mass can break and rush down. While on rocky slopes, cliffs or on lava flows, snow cover remains well on the surface. On such slopes, avalanches mainly occur in the upper layers.

How to get around an avalanche?

Since it is not always possible to avoid or bypass dangerous snowy areas, you need to know the rules for safe walking in such places.

Dangerous areas must be walked one by one, at a great distance from each other and as quickly as possible. While one of the participants passes through the dangerous area, his friends stand outside the avalanche zone and watch him, so that in case of an avalanche they can help. It is advisable to walk along the ridges of the mountains. Typically, an avalanche starts from the areas below the ridges.

When passing through a weakly expressed relief, it is advisable to choose areas with a convex relief. In these areas, due to pressure, snow cover is more stable.

Avoid the couloirs. The snow cover on them is unstable.

No matter what safety measures you take, there is always the possibility that an avalanche could occur and you could be in danger. Therefore, you must know what to do if an avalanche has begun.

There is a misconception that there are no avalanches in Armenia, or, if they start, they will not have any disastrous consequences. However, that is not true. Of course, avalanches in Armenia cannot be compared with the ones happening in Himalayas, but in any case, the risk is quite high and should not be underestimated. For example, Mount Hatis, Teghenis, Geghama Mountains can present unpleasant surprises. It is advisable to have avalanche equipment with you: avalanche shovel, avalanche transceiver and probe. It is also important to know how to use this equipment.

This is an extremely complex and long topic, and it would be impossible to fit all the information into one small article. Therefore, approach this material as an introduction. At the end of the article, we will leave links to other sources for more detailed information.

What to do when hit by an avalanche?

If the avalanche started far from you, then you will have a few seconds to leave the danger zone. Try to do it as quickly as possible.

If the avalanche began at a closer distance to you, or right under your feet, then you need to face the avalanche, stick the trekking poles or an ice axe into the snow and try to resist on it. If an avalanche begins to cover you, then you need to try to “swim” in it and try to stay on the surface. Left under the snow, people mostly die due to lack of air. Therefore, once in the snow, you need to try to dig to create airspace for breathing. Naturally, this is easier said than done. In most cases, people, especially inexperienced ones, will not be able to effectively use these techniques in a stressful situation. Still, it is better to try to do something than to stand still and panic.

Those who will look for a victim should be aware that for people left under the snow, time is extremely limited.

• After 15 minutes under the snow, 1 in 10 people are already dying.
• In 20 minutes, there will be six dead.
• In an hour, 2-3 people will survive at best.

We have provided you with basic information so that you have an idea of what an avalanche is, what to expect from it and how it occurs. This article can help you avoid dangers to some extent. However, we decided not to write about rescue operations and avalanche forecasting, since this is a large separate science, and the information about it would not fit in an article of this format. Instead, we suggest that you watch the video below in which the expert explains in detail all the nuances associated with the avalanche.

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