Thursday, April 17, 2014
Q: What causes avalanches?
A: Basically, it happens when a lot of snow breaks away from a weak layer of snow. And this has to be on terrain of a sufficient angle.
“Basically avalanches are a whole lot of bad luck,” says Jeremy Kupferman, a Professional Climbing Instructors Association certified climbing instructor and assistant winter guide at Acadia Mountain Guides in Orono.
And by bad luck, Kupferman means really bad luck. If anyone is hit by an avalanche, it is “really, really unlikely they will survive.” Avalanche.org says after 35 minutes, victims have a 27 percent chance of survival.
It’s not the trauma that does it. Kupferman says the most common cause of death in an avalanche is suffocation.
You can relax – a little. Kupferman says avalanches are common only in very specific areas in New England. That’s because there aren’t a lot of mountains where you travel above treeline for a great amount of time. He’s talking about places like Tuckerman’s Ravine below Mount Washington, and steep sections leading up Mount Katahdin.
Kupferman says you’re looking for slope angles between 30 and 45 degrees. The snow isn’t going to accumulate on slopes much steeper.
Then there are trigger points that can be dangerous.
• Leeward sides of slopes tend to collect windblown snow, which can break away.
• Exposed rocks can heat in the sun and melt surrounding snow, which weakens it.
• Changes in slope present opportunities for the snowpack to break off.
And you don’t want to be in a terrain trap like a gully, where an avalanche can bury you.
Like Kupferman says, there are a lot of variables. What you really need is a knowledgeable guide – someone who can recognize the danger areas and weak snow. Guides also should have rescue training.
One of the things they can do to assess conditions is to dig a snow pit. Then they can see the layers of snow and take temperature readings. When one layer is warmer than another, it creates weak snow. Large ice crystals form – which makes it a good candidate for breaking apart and sliding.
This diagnosis usually takes 30-40 minutes, which means you need layers to stay warm while waiting. But snow pits aren’t dug often.
Just when conditions or terrain are new to a guide.
The next thing you can do is to get some training. A level-one course certified by the American Institute for Avalanche Research and Education will teach you to analyze terrain, weather and snow pack for avalanche danger. You also will learn rescue techniques and how to use tools such as a probe and shovel.
Once you gain some education, Kupferman is a big proponent of practice. Go out with friends and practice how to use the tools and skills.
Again, it’s about preparation. Avalanches are bad luck. Avoiding and surviving them are about skill and experience.
Carl Natale is a Registered Maine Sea Kayak Guide, hiker and content producer for MaineOutdoorJournal.com. Send questions to: