Devastating and fascinating, avalanches should be admired from afar! Avalanches can pose a threat to anyone on snowy mountainsides. They can be deadly because of their unpredictability and intensity, so all hikers, skiers and snowboarders out there should be more than careful! How to stay safe? Maybe our best tool to stay safe and yet enjoy the mountains’ snow slopes is knowledge and understanding of avalanches.
Start by learning the various types of avalanches, the circumstances under which they might occur, and how to survive if we come close to one. For a better understanding of this natural phenomenon and its power, we’ve prepared 40 interesting facts about avalanches that’ll keep you safe on and off the mountain slopes…
When do avalanches occur? When snow rapidly flows or slides downwards.
Avalanches are often called a snow slide or a snow slip.
An avalanche can be a result of loose snow, which isn’t so critical or fatal. It can also be created from a slab of snow that slides as a unit and consumes and destroys almost everything in its way.
Powder, Wet Snow, and Slab are the three types of avalanche.
The most common are slab avalanches that reach between 60 and 80 mph.
Slab avalanches are also the most deadly avalanches.
In a slab avalanche, the mass of sliding snow may reach a speed of 130 km (80 miles) per hour.
Most avalanche accidents occur as a result of the victim or someone in their group triggering the avalanche.
Every year more than 150 people worldwide are killed by avalanches.
The factors responsible for the creation of avalanches are: a steep slope, a weak snow layer, the snow cover, and a trigger.
What’s a trigger? It’s usually the weight of you or a friend.
Predisposed to avalanche is a slope of 30 degrees or above.
Every skier or snowboarder should be familiar with the avalanche’s kit. It should have a transceiver, a shovel, a probe, and most importantly know-how!
There’s a higher avalanche risk 24 hours after a snowfall of 12 inches or more.
In a short period, an avalanche can reach high speeds, as fast as 80km an hour in only 5 seconds.
Crews trigger avalanches on purpose in some areas under safer conditions in order to reduce the build-up on unsafe slopes.
The human body descends in the avalanche debris very quickly.
When the avalanche slide begins to slow down, a buried victim should clear up space to be able to breathe and punch their hand up, before the snow slide stops.
If rescued in 18 minutes or less the survival rate of a victim buried by an avalanche is 91%.
The survival rate of victims is only 34% when the rescue happens between 19 and 35 minutes after the avalanche.
The worst avalanche disaster occurred in the United States in 1910. Approximately 96 people died as a result of an avalanche triggered by a train wreck.
The deadliest avalanche on a global scale may have happened more than 2,200 years ago when Hannibal tried to march the Carthaginian army across the Alps from Spain to conquer Rome. It’s believed that the avalanches in the Alps have killed 20,000 of his men.
The size of a snow avalanche can vary from a small shifting of loose snow to the shift of enormous slabs of snow.
To kill the enemy troops avalanches have been triggered intentionally.
During World War I, approximately 40,000 to 80,000 soldiers died as a result of avalanches at the Austrian-Italian front.
There were 265 people killed in avalanches in the Alps of Germany, Italy, Switzerland, France, and Austria in the 1955-51 winter season. The avalanches were referred to as the ‘Winter of Terror’.
The Himalayas are the home of the largest natural avalanches.
Avalanches can reach speeds of 200mph, reach a mass of more than a million tons, and achieve forces 48 times stronger than those needed to demolish a frame house.
Harsh avalanche can leave behind acres of destroyed buildings, snap trees like toothpicks and dump snow in 30-foot-high loads.
Destroying everything in their path avalanches flow like rivers of icy cement.
High population density is one of the main causes of avalanche disasters.
Many buildings are being built, many trees are being cut and many resorts are being built higher up in the mountains, where there is no protection from avalanche whatsoever.
Be careful! Even if the snow looks stable that doesn’t mean there is no risk of an avalanche. There could be an unstable snow layer just a few millimetres or a few centimetres thick, just below the surface.
Even air currents produced by an avalanche present great danger.
Even if the main avalanche stops and the slope levels out, still the air currents continue forward and carry significant amounts of snow.
Gusts of wind can cause destruction far from where the main avalanche stopped.
There are surface avalanches with a speed of 300kph that kick up snow clouds hundreds of meters high.
On a typical surface avalanche, a one-centimetre-thick “weak layer” of loosely joined snow particles lay under 90 centimetres of surface snow. If there’s additional weight from snowfall or rising temperatures that causes the weak layer to partially melt and become more slippery, the avalanche can be triggered.
The greater the snowfall the more likely an avalanche is to occur.
To sum up and stay safe! If you’re planning to travel into the backcountry and up a mountain, get the know-how from these facts and take an avalanche safety course!
Do you have any interesting or fun facts about avalanches that we’ve missed? Share them here in the comments section below!