Surely you have ever heard or seen some avalanche de snow or rocks. In numerous films or documentaries you can see how the avalanches cause numerous destruction as well as some deaths due to burial and suffocation. In this article we are going to know in depth how avalanches form and what consequences it has. Is there a method of containment or prevention of these phenomena?
If you want to know more about it, you just have to keep reading this article because we will tell you everything in detail.
Definition and characteristics
Before knowing what consequences it can have or how to stop it, it is important to know what an avalanche is. The most common is that it is a snow avalanche. Is about a great mass of snow that, due to its accumulation, ends up collapsing through the mountains. It is the slope together with the accumulation of snow that causes the snow to precipitate by its own weight. Let's not forget that gravity is continuously doing its thing and pulling all that snow down to the lowest heights.
The main characteristics of avalanches are the rapid flow and the speed with which they move. Be it avalanches of snow, rocks, earth, ice, etc. When we refer to a rock avalanche it is a set of rocks on a slope that, for weathering physical or chemical, it ends up fracturing and precipitate due to the effect of gravity.
For many people it is one of the most impressive natural events to see, but at the same time very dangerous. Many skiers are able to navigate downhill with great speed and dexterity. However, the speed at which a snow avalanche falls is much faster.
If the mass of snow is unstable and is formed on a slope, when falling, its speed increases as it descends in altitude. The noise it forms is enormous and echoes in the rest of the mountains. When it ends up precipitating on the bottom where the slope has decreased, it causes a large cloud of ice particles resulting from the impact. These ice particles end up scattered in the air and melt away.
Causes of avalanches
Snow avalanches can weigh around a million tons. Imagine that you are skiing calmly enjoying the views and the adrenaline that descends at high speeds causes and you find that you are being chased by a million tons of snow. The result is dire. Most of the skiers who are hit by an avalanche of snow die buried in it.
Also, not only do you end up dying because you are buried, but you have to bear in mind that the million tons are frozen and you suffer from hypothermia. But what is it that causes an avalanche to occur? For an event of such magnitude to exist, a large amount of snow is needed. Snow packed onto a slope is a perfect trigger for a landslide.
They usually form on slopes with an angle of inclination of between 25 and 60 degrees on the slope. It is in this case where, when the snow is stored, it can precipitate by gravity. But another ingredient is also needed for the formation of the avalanche and that is that there has been a snowstorm that is capable of storing about 30 centimeters of snow to the upper layer in a short time. Snow must be stored for at least 24 hours so that, by compaction, it can precipitate as we weigh more and more.
The bonds between the snow layers have to be weak so that they can become unstable. It is common that, when the snow is crowding, there is a layer that is more unstable. The sudden change in the weather in the area is the trigger for the avalanches. It can also be the fall of a tree, a small earthquake or too loud noises such as a fair or a loud speaker.
Types and effects of avalanches
When the million tons of snow falls to the ground it finally compacts. According to the types of avalanche regulated by intensity and some other characteristics, a classification has been created to make it easier to recognize and study. We divide them into:
- Plate avalanches. These are those formed as a result of weak layers of snow that are found in the lower part of the mountains and, when breaking, a large area of snow is sliding down the slope.
- Wet snow avalanches. These are those in which the snow moves at lower speeds, but the snow is very dense.
- Avalanches of powder snow. This type is the one that forms a great cloud of snow dust that glides at high speed and traveling long distances.
There are several negative effects that avalanches cause when taking place in an area. The first and most important is to bury large areas of land where people, animals, plants, buildings, etc. can be built. It destroys a large part of the ecosystem in which it is found and, strangely enough, it can cause a strong wind blows when compacting the air.
The most tangible effects are the sweeping of vehicles, collapse of trees and destruction of buildings. They are really quite dangerous events that must be avoided at all costs.
Curiosities
The danger of avalanches increases when skiers are in full swing and encounter one of these phenomena. This is very difficult to prevent and predict, so if you are surprised and the snow is fast flowing, you are done. However, here are some of the curiosities related to the subject:
- Every year more than 150 people die from avalanches.
- It is possible to rescue those affected if you remove from the interior in a 15 minute period with a 93% probability margin of success.
- There were more soldiers killed by avalanches than by poison gas in World War I.
- The time of year when they are most frequent is in winter and spring.
I hope this information helps you learn more about the subject.