Language
Country/Area
No result found
The destructive power of winter nature: How much do you know about avalanches?
An avalanche is a rapid flow of snow on a slope. This natural phenomenon usually occurs on hillsides or mountains and can pose a serious threat to life and property.
Avalanches can be triggered by nature or external forces, including rainfall, earthquakes, the activities of other animals, and even human behavior. There are a number of key factors that can make a snowdrift unstable, such as increased snowfall or a weakening of the snow's structure. Avalanches are primarily composed of moving snow and air, and large avalanches have the ability to capture and move ice, rocks, and trees.
This powerful natural phenomenon mainly takes two forms: one is a slab avalanche composed of tightly packed snow, which is usually triggered by the collapse of the underlying weak snow layer; the other is a slab avalanche. A loose snow avalanche is composed of loose snow. When an avalanche is triggered, it usually accelerates rapidly and increases in mass and volume as it captures more snow. When an avalanche moves at sufficient speed, some of the snow may mix with air, forming a powder snow avalanche.
Avalanches can occur in any mountain range with persistent snowdrifts, especially in winter and spring, but they can happen at any time.
In high mountain areas, avalanches are one of the most serious natural disasters. In order to reduce the damage, avalanche control efforts have been carried out in many places. Many classification systems exist to describe different forms of avalanches, including descriptions based on their size, destructive potential, triggering mechanisms, composition, and dynamic characteristics.
Avalanche formation
Most avalanches occur spontaneously during storms, primarily due to loading caused by snowfall and increased erosion. Deformation processes in snow packs, such as melting due to sunlight exposure, are the second leading cause of natural avalanches. In addition, rain, earthquakes and rock slides can also trigger avalanches. Avalanches are triggered artificially by skiers, snowmobiles, and controlled explosives.
Contrary to popular belief, avalanches are not triggered by loud noises because the pressure of the sound is nowhere near enough to trigger an avalanche. An avalanche usually begins where only a small amount of snow in the snowpack begins to move, usually in a wet snow avalanche or dry loose snow condition. When snow forms a hard plate-like structure on top of a weak layer, cracks may expand rapidly, and several cubic meters of snow will begin to flow almost simultaneously.
Further research is helping to develop computer models to describe the evolution of seasonal snow packs over time, revealing significant spatial and temporal variability resulting from the complex interaction of topography and weather.
Types of avalanches
Avalanches can be divided into several different types, including slab avalanches, powder snow avalanches, and wet snow avalanches. Slab avalanches tend to occur in wind-affected snow and have the characteristic appearance of cut snow chunks. These slab avalanches often cause major accidents, accounting for approximately 90% of avalanche-related fatalities. In addition, powder snow avalanches are formed by a mixture of snow and air in a turbulent suspended flow. This type of avalanche can move at speeds in excess of 300 kilometers per hour.
In contrast, wet snow avalanches travel at a slower speed, usually between 10 and 40 kilometers per hour, but they can produce powerful destructive force. This is because of its mass and density, which allow it to sweep over boulders, trees and other vegetation as it flows, leaving a noticeable mark.
The occurrence of avalanches is closely related to the complex interaction of terrain, snow packs and climatic conditions, which requires people's great attention and prevention.
Avalanche hazards
According to statistics, between 1950 and 2021, 1,169 people died in avalanches in the United States. In North America, a total of 445 people were injured or killed by avalanches in the 11 years before 2006. Every winter, an average of 28 people are killed by avalanches. Behind these figures, not only show the fatality of avalanches, but also reflect the dangers of human beings in winter outdoor activities.
As weather patterns change due to climate change, the frequency of avalanche events is gradually increasing. Therefore, understanding the truth about avalanches and studying how to predict and prevent them are extremely important topics.
Exploring avalanches is not only a scientific challenge, it also tests our understanding and adaptability to the living environment.
Before you plan to travel to snowy areas, do you really understand the potential dangers and preventive measures of avalanches?
