Avalanche: Danger Lurking in the Snow

20 December 2012
Published in Environment
Written by  Kim Schuske
Avalanche: Danger Lurking in the Snow Scientif38, Creative Commons

Now that it’s winter, the siren call of snow has people going into Utah’s backcountry to ski, board, and snowmobile. But avalanches are a constant danger. On average 27 people die each year in the Mountain West, with the death rate peaking in January.

Bruce Tremper was 24 years old and building chair lifts at Bridger Bowl ski resort in Montana. After finishing his work, he only had to ski across a short steep narrow gully to get to a safe slope and was confident he could get to the other side before anything bad happened. But Tremper found out, when a slab breaks and the snow slides at speeds of 65-80 miles per hour, there’s not even time to react.

“When you trigger an avalanche the first thing that happens it feels like somebody pulls a rug out from underneath you. And you just kind of flop on your side and you go, oh my god what’s happening, and by the time you say that, those words come out of your mouth, it’s too late," says Tremper.

"It tumbles you, you don’t know which way is up. Snow goes everywhere, every time you take a breath, your breathing this mixture between snow and air, it goes under your eyelids, down your underwear, everywhere, it rips off your mittens and goggles instantly, it breaks your skis. That snow gets ground up and heated up on the way down and when it comes to a stop--its just solid like concrete, you cannot move. You cannot get yourself out, someone else has to get you out.”

Tremper was alone and didn’t have any safety equipment. But that day in 1978, he was lucky. He grabbed onto a tree and a lot of the debris passed him by. Eventually the tree broke throwing him to the bottom of the slope. When it came to rest, he was only buried up to his waist and escaped. Tremper says that day he realized it was time to learn everything he could about avalanches.

He’s now the Director of the Utah Avalanche Center. “And they’re extremely deadly, but they’re really, really impressive. You can’t stand next those and watch them go off without it changing your life, it’s impossible,” says Tremper.

25% of avalanche victims die from trauma, being hit by trees or other debris, and only 2% survive long enough to die of hypothermia—its the carbon dioxide that gets most people. Tremper says a person who is buried has fifteen minutes to get out. “Even though there is plenty of air in the snow to breathe, that is not the problem. But the carbon dioxide builds up in the snow around your mouth and that’s what kills you, asphyxia. So in other words carbon dioxide poisoning.”

Inventions that Save Lives

Two recent inventions are saving the lives of people that do get caught in an avalanche. The first is the Avalung. It’s a device that separates the carbon dioxide that you breathe out from the air your breathing in. It’s produced by Utah’s outdoor equipment company Black Diamond. Temper says he wouldn’t think of going into the back country without one.

“And it’s a brilliant device, but it’s just a tube that you wear either on your pack or underneath your pack," says Tremper. "And then if you get caught in an avalanche you just put the tube in your mouth, hopefully you can get it in your mouth, and then it’s got a little flapper valve on it so when you breathe in the air comes in through a screen in the front that screens out the snow. And when you breathe out the carbon dioxide comes out the end of the tube which around on your back.”

Tremper says the Avalung can extend a person’s life under the snow for up to an hour. But nothing compares for safety to the avalanche air bag.

“If you get caught in an avalanche you just pull the rip cord and then they blow up these avalanche air bags outside of the pack and so it floats you to the surface just like a lifejacket would in the river," says Tremper. "These avalanche airbags there has been almost 300 real life cases so far world-wide and the statistics are running really consistently at 97-98% success rate. That’s way better than anything that’s ever come along before.”

Know the Snow

Of course the best way to avoid dying in an avalanche is to not get caught in one in the first place. Forrest Shearer is a professional snowboarder based in Salt Lake City and constantly has to worry about avalanches. He does backcountry snowboarding and took it to a new level in the movie--Deeper.

“We hike and ride mountains. The hiking is anywhere from 1,000 vertical feet to 5,000 plus vertical feet. So it’s hiking straight up mountains," says Shearer. "We were using crampons and ice axes, so for us it was a new aspect to get into and to combine into our world of snowboarding.”

The movies snowboarding team hiked and boarded mountains across the world. Shearer says the riders carried advanced gear such as the Avalung and avalanche airbags, but knowing the snow was the most important thing for keeping safe. He says from the time they wake up in the morning to the time they board down the mountain, they are constantly looking for red flags that would prevent them from continuing. Because of strong safety measures, none of the members of the team was injured in an avalanche.

“The mountains are a really powerful place and we need to respect that. So if anything is not right with what your doing its like the snow will always be there for us in the mountains so you can always do it another day you know.”

Shearer says they look for danger signs of a strong cohesive layer of snow over a weak layer. Obvious warnings are a heavy snow that fell overnight, or snow that has been blown and piled up by the wind. But he says digging snow pits and knowing what to look for in the layers is essential.

Bruce Tremper agrees, “Most people just dig down in the snow and they just see a bunch of white, but if you’re an avalanche scientist it’s just this vast world of all these different layer. And some of the layers are strong and some are weak. Those weak layers fracture, they collapse, and the energy from that collapse propagates out and just shatters the whole slab, the stronger overlying snow.”  

Tremper says most of the recent deaths are untrained people that go out of bounds at ski resorts or ride snowmobiles. He says the best way to stay safe is to pay attention to daily avalanche forecasts, take an avalanche safety class, and carry safety equipment when going into the backcountry.

He says it’s a lesson his father tried to teach him. It finally sank in, the day he almost died in 1978.

This story originally aired 1/10/11.

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