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The Question of Avalanche Preparedness

Andrew McLean

Peter, Mugs, Steve, Alex, David, Roman, Doug, Julie and Dave. Nine experienced friends that have died in avalanches and yet I'm still making plans to backcountry ski in the Purcell Mountains over New Year's. It makes me wonder if I'm completely delusional, totally ignorant or just outright stupid. Perhaps a little of them all.

Education is a key element in avoiding avalanches, but the plain truth is that there is really only one way to avoid them - stay out of snow covered mountains. This seems to be easier said than done for many of us and we always find ways to rationalize going back for more.

With 20' crown lines and over 5,000' of vertical drop, Himalayan and Alaskan avalanches are the largest in the world. When it comes to destructive power, they fall into the same category as earthquakes, tsunamis or tornadoes and are easily capable of destroying manmade structures and even small villages. Watching them from a safe location emotes a deer-in-the-headlights type of response - you know that you shouldn't be anywhere near them, yet at the same time it's such an amazing, thrilling sight that you seem unable to do anything more than stare wide-eyed at them.

Avalanches require three things to occur; a trigger, a bed surface and a slab. Depending on the sensitivity of the slab, the trigger can be something as innocuous as a bird landing on a slope, a chunk of cornice falling off or just one snow crystal too many getting blown onto a lee slope. Once in motion, you never know where they are going to go. Sometimes they just fizzle out and stop, but oftentimes they act as triggers for other sensitive slabs in the area, which starts a chain reaction known as "propagation."

Seen from a distance, propagation looks like horizontal lightning flashing across the slope - large cracks shoot down ridgelines, hang for a fraction of a second, then huge curtains of snow start to slide downhill. Once in motion, this mass of snow can again act as a forceful trigger, propagating downward and setting off deeper layers of snow that may have been marginally bonded to each other, so that a 2' deep slab suddenly becomes a 5' slab, which in turn can trigger a 10' slab, etc.,...

As they crash downward, they tear out old ice seracs and loose rocks until they are a churning mass of flying debris often going over at 120mph. Imagine a medium-sized office building falling over and crashing through the streets at that speed and you have a close approximation of the size and force of a class 5 avalanche. To get caught at ground zero in one like Alex and David did and then get propelled through a crevasse field, is hard to even imagine. To survive one like Conrad did, is a miracle.

There are many precautions you can take when you are traveling in avalanche terrain, including wearing a beacon, carrying a shovel and staying spread out from other people. In hindsight, people have questioned why none of these basic rules were followed. The simplified answer is that we didn't consider what we were doing or where we were going that day to even remotely have any sort of avalanche hazard. You could drive a golf cart up the glacier we were on and there wasn't a trace of new snow. The sky was clear and sunny and there was little to no wind.

I was on rock most of the way and Alex, David and Conrad were on hardpacked old snow. After a big effort the day before, the plan was just to walk up a little higher and get a look at the skiing objective for future reference. About the only safety equipment any of us carried that day was sun lotion. In many avalanche accidents, the victims are often the ones that caused the slide - often unwittingly acting as the trigger. In Alex and David's case, it was a complete act of fate. Had they been five minutes earlier or later, the slide would have missed them. It was started by some unseen event thousands of feet above them and was totally unrelated to them being there. Having witnessed it from close enough to get covered by the powder blast, I'm certain that even if we had been wearing beacons that day (we had them with us on the trip), it would have been a grim matter of body recoveries instead of a joyful excavation.

In retrospect, it's hard to think of anything that I we should have done differently, aside from just not going there in the first place.

Andrew McLean, Correspondent


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