A recent news story said a person survived an avalanche in part because he had a piece of gear that drew air from snow allowing him to breathe even though buried. Details?

Probably referring to the Ava-Lung by Black Diamond.

Thanks. Interesting gizmo.

In most snow avalanches (excepting very wet slides), there is actually quite a lot of air in the snow. If you aren't killed by trauma, and aren't buried too deep (where the weight squeezes your chest so you can't inhale), then you can breathe for awhile.

What happens over time is that the CO2 you exhale builds up around your face in the snow. Also, the warmth of your breath tends to slightly melt the snow against your face, which then refreezes. This builds up an ice mask over your face, which tends to be impermeable to air. So over time you suffocate from some combination of excess CO2 and ice sealing your face. On body recoveries, the presence of an ice mask indicates that the person lived for at least awhile after being buried. That is why fast rescue is so critical. If you're not otherwise injured, and are dug out in less than roughly 15 minutes, your odds are fairly good. After 15 minutes, chances of survival drop very rapidly.

The theory of the avalung is that it has a mouth peice somewhat like scuba gear, and a couple of tubes and valves. When you inhale, it takes in air from one valve, and when you exhale it is vented out somewhere else, away from the intake. So you don't rebreath your own CO2 and the ice mask forms away from your face. Avalungs have been shown to work in some cases.

An AvaLung can buy you some time IF:

1. You can manage to get the mouthpeice in while getting the "Maytag" wash inside the equivilent of a cement mixer.
2. You aren't killed outright by trauma (about 25% of avalanche deaths are thought to be due to trauma, not suffocation).
3. You aren't buried too deep (if buried deeper than about 2 meters almost no one survives, probably due to the weight of the snow).

See AvaLung by Black Diamond, and also AvaLung Review.

Not getting buried in the first place beats any peice of gear!

Thanks.

The avalanch airbags have a better recorded history in there effectiveness and seams to be a beter avalanch survival tool.

Maybe. I haven't seen any detailed statistical comparison.

Airbags have been known to help: Air bag backpack likely saved former Alaskan. "In all, the avalanche had swallowed three other skiers. Saugstad, a professional downhill skier who grew up in Girdwood, was the only one of the four wearing the air bag backpack -- and the only one to emerge alive."

On the other hand: Soules ... had the latest ... backpack air-bag system... "The important thing to realize here is that thing was completely soaked in blood," he said of the air bag. "It certainly deployed, but I didn't think it would have made any difference."

My concern is that people are using these devices as an excuse to cut their safety margins thinner than they would otherwise. I worry they think because they have a beacon, avalung, airbag or whatever, that it's OK to ski in conditions that they would have avoided if they didn't have these devices.

On of the fatalities in CO this year the mans airbag was inflated, but shredded (i think he had an avalung as well). They definitely save lives, but nothing is foolproof.

Also, while the airbag may be more effective, it also costs 10X more (> $1000). Sure, safety is worth it, but that is still a lot of money.

Whenever you're spending money on security or safety, you should look at what else the money could be spent on more effectively. Is there something else that costs the same or less and would provide the same or better improvement in safety?

You're also "spending" weight and bulk. In some endeavors, weight and bulk can be the enemy of safety, or prevent you from carrying something else that would be more useful.

I'd like to emphasize that I don't begin to know enough about avalanche airbags to have an opinion about them one way or another. I'd like to hear from people who know more than me about these issues.

FYI -- Avalanche airbag -- ABS TWINBAG-- Just so we know what this thing is.