How to Survive an Avalanche: Gear, Terrain and What to Do If Caught

Most people who die in avalanches are skiers, snowboarders, snowmobilers and climbers who set off the slide themselves. That is the hard truth behind avalanche safety, and also the good news: the best way to survive an avalanche is to avoid being caught, and the second best is to travel with partners who carry the right gear and know how to use it fast.

Where and why avalanches happen

Avalanches usually start on slopes of 30 to 45 degrees. Slopes gentler than about 25 degrees or steeper than 60 degrees release far less often, and the most dangerous angle for human-triggered slides is around 38 degrees, which happens to be the pitch of a fine powder run. In recreational accidents, about 83 percent of avalanches are triggered by people involved in the accident, typically by adding their weight to a slab of snow resting on a weak layer.

Terrain shapes the outcome as much as the slide. Gullies, creek beds and depressions act as terrain traps where debris piles up metres deep. Trees, rocks and cliffs cause the injuries that account for a large share of deaths. Before committing to a slope, look at what lies above it and what lies below it.

In Europe, avalanche bulletins use a five-level danger scale adopted in 1993, from 1 (low) to 5 (very high). Most fatal accidents happen at levels 2 and 3 in Switzerland and at levels 3 and 4 in France, when many slopes look tempting but are only moderately or weakly bonded. Read the bulletin for your region every day you go out.

The essential avalanche gear: transceiver, probe and shovel

Avalanche Canada is blunt about it: everyone in the group needs a transceiver, a probe and a shovel, and one or two of the three is not good enough. Each tool does a different job.

• Transceiver (beacon): worn on the body in transmit mode, switched to search mode to locate a buried partner. Modern three-antenna digital units are the standard.
• Probe: 240 cm is the shortest standard length and covers most burials; 320 cm suits deep snowpacks.
• Shovel: a sturdy metal blade, as large as fits the pack, ideally with an extendable shaft. Digging takes far longer than searching.

Keep phones, radios and other electronics about 20 cm from your transceiver when transmitting and 50 cm when searching. An airbag pack can keep you nearer the surface and reduce burial depth, but you can still be buried in a terrain trap, so it is an addition to the three essentials. Take a recognised avalanche course and practise beacon searches before, during and after the season.

What to do if you are caught in an avalanche

Karl Birkeland, director of the US Forest Service National Avalanche Center, sums up the first priority: get off the moving snow. Survivors' accounts and avalanche educators point to the same sequence:

1. Escape to the side. As the slab breaks, ski, ride or run towards the flank of the slide, where the snow moves slower.
2. Grab an anchor. If you are knocked over, grab a tree or rock to slow yourself.
3. Fight to stay on top. Swim, roll and thrash to keep your head near the surface. Ditch a snowboard or sled if you can, and never strap ski poles to your wrists.
4. Make space as it slows. In the last seconds before the snow sets like concrete, thrust one hand towards the surface and use the other hand or an elbow to clear an air pocket in front of your mouth.
5. Stay calm. Once fully buried, conserve air and energy; your partners are your rescue.

Companion rescue: why the first 15 minutes matter

A buried person usually dies from asphyxia, not cold. A 2011 study in the Canadian Medical Association Journal compared 946 Swiss and 301 Canadian burials. In Switzerland, more than 91 percent of victims survived if they were dug out within about 18 minutes; between 19 and 35 minutes survival fell to 34 percent. Canadian survival dropped even earlier, so the authors recommend aiming to free victims within 10 minutes. In the Canadian data, 81 percent of deaths with a known cause were due to asphyxia and 19 percent to trauma.

Organised rescue teams rarely arrive inside that window, which is why the people already on the slope matter most. Watch the victim and mark the last-seen point, check the slope is safe to enter, switch every beacon to search, then probe and dig. Call emergency services as soon as someone can do so without slowing the search. Shovel in from the downhill side, not straight down, and work in rotation.

Caught on camera: Matthias Giraud and Mikey Wier

The first video below is snowboarder Mikey Wier's helmet-camera footage of being caught in an avalanche. The second is the famous GoPro clip of French ski-BASE jumper Matthias Giraud, nicknamed "Super Frenchie", who grew up skiing around Saint-Gervais and Megève. On the morning of 25 April 2011 in the French Alps, he skied towards a cliff for a parachute jump and set off an avalanche that chased him to the edge. He launched, opened his canopy and flew clear while the slide poured over the drop. His friend Stefan Laude, a local paraglider and speedflyer, filmed the scene.

For two very different rescues, read about Aymar Navarro's airbag deployment in the Pyrenees and the East Vail companion rescue.

Related reading

• East Vail Avalanche Rescue: The December 22, 2013 Footage
• Iain Stewart’s Avalanche Documentary: Stories and Snow Science
• Aymar Navarro’s Avalanche Incident in the Spanish Pyrenees

Sources