I have been doing a bit of research for another story.
Along the way, I started researching avalanches. For no reason. No reason at all…
Anyway, I thought I would share the results of some of that.
Five Things You Thought You Knew About Avalanches But Were Wrong
1. Avalanches are not triggered by sound.
That is correct. It’s a plot point in many movies, but noise simply does not have enough force to trigger an avalanche. I was more than a little surprised by this, though I should know by now Hollywood spins a good story, not necessary an accurate one.
2. Avalanches are seldom random.
Those sudden and inexplicable snow slides you see in the movies? Very unlikely. In 92% of all avalanche accidents, either the victim or someone in the victim’s party triggered the avalanche. So while a tree falling in the woods is enough to displace the snow pack, it is usually the force of skiers over the snow that causes the snow to break free and start falling down the mountain.
3. Avalanches are not fluffy
You’ve seen the images. The brilliant puff of white snow that hail the impending avalanche. Except in most cases, that isn’t what an avalanche looks like at all. They usually travel at approximately 80mph in one dense slab. They are powerful forces of nature that take down trees, boulders, and other debris with them.
4. Avalanches Don’t Start with a Bang but a “Whumph”
Avalanches tend to happen when there is more than one kind of snow on the ground. For example, an original layer of snow that is then covered by fresh snow. The fragile needle-like crystals connecting the new snow to the older snow can be easily broken. Even by the weight of a skier. The weight of the skier can have a ripple effect through the snow, and this can cause the upper layer of snow to collapse by as little as a millimeter. This collapse is often accompanied by an audible “whumph” of settling snow. This settling produces enough energy to shatter the fragile crystals and tends to propagate uphill, leading to a major release of the upper layer. The rest is up to gravity, friction, and the steepness of the mountain.
5. Avalanches Don’t Freeze You To Death
While cold is certainly a factor, most deaths from avalanches are caused by trauma and asphyxiation. Approximately 30% of people caught in an avalanche die from trauma. While you can sometimes swim through snow, once it comes to rest, it will be packed around the victim as hard as rock, squeezing the air out of their lungs. Victims of an avalanche who survive the trauma have a 90% chance of survival if they are rescued in 15 minutes. If they are freed in 30 minutes, the odds are down to 50%. In the event of a significant avalanche dropping more than 6 feet of snow, the odds of the victim surviving are almost zero.
I am not a skier, and I am definitely not a back country skier. After reading a lot of this research, I understand why it considered such a dangerous sport. Still, it does present some interesting “opportunities” for characters.
*evil author laugh*