You've probably heard of or seen a snow or rock avalanche at some point . Many movies and documentaries show how avalanches cause widespread destruction and even death due to burial and asphyxiation. In this article, we'll explore in detail how avalanches form and their consequences. Are there any methods for containing or preventing these phenomena? If you want to learn more, just keep reading this article because we'll tell you everything in detail.
Definition and characteristics
Before understanding the potential consequences or how to stop an avalanche, it's important to know what an avalanche is. Most commonly, it's a snow avalanche. This is a large mass of snow that, due to its accumulation, eventually collapses down the mountainside. It's the slope, combined with the snow accumulation, that causes the snow to fall due to its own weight. Let's not forget that gravity is constantly at work, pulling all that snow down to lower elevations. To learn more about this natural phenomenon, you can read about the characteristics and formation of snow avalanches.
The main characteristic of avalanches is their rapid flow and speed. This applies to avalanches of snow, rocks, earth, ice, and other materials. A rock avalanche is a collection of rocks on a slope that, through physical or chemical weathering , fracture and then fall due to gravity. For those seeking more information about the impact of snow, you can find interesting facts about snow and its environment here.
For many people, it's one of the most impressive natural events to witness, but also one of the most dangerous. Many skiers are capable of moving downhill with great speed and skill. However, the speed at which a snow avalanche falls is much faster. If the mass of snow is unstable and formed on a slope, its speed increases as it descends. The noise it creates is enormous and reverberates throughout the rest of the mountains. When it finally plunges to the bottom where the slope has decreased, it creates a large cloud of ice particles from the impact. These ice particles are then scattered in the air and melt.
Causes of avalanches
Snow avalanches can weigh around a million tons. Imagine you're skiing peacefully, enjoying the views and the adrenaline rush of descending at high speeds, and suddenly you're being chased by a million tons of snow. The result is disastrous . Most skiers caught in an avalanche die buried under it. To better understand the magnitude of this phenomenon, it's important to know that in addition to being buried, the million tons of snow is frozen, and you suffer from hypothermia. But what causes an avalanche? For an event of this magnitude to occur, a huge amount of snow is needed. Snow piled up on a slope is the perfect trigger for a collapse.
Avalanches typically form on slopes with an angle of inclination between 25 and 60 degrees. It is in these cases that, as snow accumulates, it can precipitate due to gravity. However, another ingredient is also necessary for avalanche formation: a snowstorm capable of depositing about 30 centimeters of snow onto the top layer in a short period. The snow must remain accumulated for at least 24 hours so that, through compaction, it can precipitate as it becomes heavier. For additional information on the weather and its effects, you can consult the article on the cold wave in Japan , as well as explore more about the changes in the Alps and their snow.
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.
Avalanches have several negative effects when they occur in an area. The first and most significant is the burial of large areas of land, which can include people, animals, plants, buildings, and more. They destroy a large part of the surrounding ecosystem and, although it may seem strange, can even generate strong winds by compressing the air. To better understand this phenomenon, you can read about the impact of snow in the Swiss Alps and its relationship to avalanches.
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.
