Worried about avalanche risk? Learn the main causes and become one step safer…

19 December 2018 mountains in winter

It was once believed that the echo of a human voice was in its self, enough to trigger an avalanche by dislodging snow with vibrations. And although this is technically possible, the chance of this occurring is very slim. The amount of vibrations needed to make the snow start sliding would need to be significant. And also a chain reaction would need to occur in a way that where one piece of snow begins to slide, so would another.

The much more likely explanation for an avalanche would be a combination of human and natural factors. Which we have discussed further in this blog.

What are the most likely causes of an avalanche?

According to current scientific understanding, there are a number of factors which could trigger an avalanche. Including:

Snowstorm and wind direction. A heavy snowstorm can result in the occurrence of an avalanche. However, this is most likely to occur within the first 24 hours of a snowstorm. As the wind blows from one side of a mountain to another, snow is scoured from the surface which can eventually overhang a mountain.

Heavy snowfall. When snow deposits its self in unstable areas, increasing amounts of pressure are placed on the snowpack. Increased precipitation during the summer months can be a significant factor resulting in wet snow avalanches.

Layering of snowfall. In cold conditions, snow will eventually turn to ice. Then on top of this, more snow will build up which will eventually slide from the slippery surface below. Resulting in an avalanche.

Steep slopes. Steep slopes can contribute to avalanches because as layer upon layer of snow builds up, the snow will eventually not be able to take any more weight and will slide down the slope at great speed. If this wasn’t bad enough, large pieces of ice and debris can also descend, bringing with it even more snow.

Warm temperatures. Warm temperatures can cause the upper layers of snow to melt which causes these to slide down the mountain.

mountains in winter

Humans can also contribute to avalanche risk

Human activity. Human activity can be a major cause of avalanches. Particularly the frequent occurrence of winter activities which take advantage of steep slopes. Through such activities, extra pressure is added to the snowpack. When combined with other human activities such as deforestation and soil erosion, the soil becomes unstable and eventually collapses, causing an avalanche.

Vibration and movement. Use of vehicles such as snowmobiles can be a major factor causing conditions leading to avalanches. Another common way that an avalanche may occur is through the use of explosives during construction projects.

What are the main risk factors that can cause avalanches?

It was once believed that the sound of a human voice could trigger an avalanche through the vibrations emitted through the echos which would supposedly dislodge snow, causing it to cascade down a mountain. While being technically possible, the chance of this occurring is very rare. The more likely explanation for an avalanche to occur would be human and natural factors. Mainly weather conditions, slope angle and vibration and movement caused through human activity.

Avalanches can be very dangerous and the consequences can be severe if individuals do not react or deal with an avalanche in the correct way. At North East OA, we have recently launched an Avalanche Avoidance course, This one day course, based in the Cairngorms National Park, is perfect for individuals with some experience in winter hillwalking, mountaineering or climbing that would like to learn how to keep safe in areas prone to avalanches and what to do in such a situation. If this sounds like a good choice for you, why not book the Avalanche Avoidance course today through North East OA or perhaps look at the other Winter Mountaineering courses we have available?