Tuesday, January 02, 2007

Avalanche catches local glissaders on Loveland Pass

A story in the Gazette today reported that father and son Stan and Mark Gingrich of Monument were hiking along the Continental Divide when they triggered an avalanche just south of Loveland Pass. The slide, on a western aspect, ran an estimated 500 vertical, feet, and was 300 feet wide with a fracture about 1 to 1.5 feet deep. They were able to rescue themselves. Avalanche danger at the time was moderate with pockets of considerable. These two are astronomically lucky to be alive.

I want to do a little bit of Tuesday-morning avalanche forecasting here. Obviously hindsight is 20/20 and I don't mean to criticize the pair, but I think it is beneficial to look back at incidents to see what can be learned.

I was skiing at A Basin Sunday when the slide happened, less than a mile away. It was a gorgeous, sunny, calm day. My skiing buddy Hunter, who does avalanche safety and ski patrol in Summit County commented as we were driving to the ski area that it was exactly the kind of weather when people die in avalanches. Blue skies inspire false confidence, he said.

When we got to the top of A Basin, we looked out at the alpine bowls of Loveland Pass. It had snowed six inches in the area three days before, and there had been some wind. Not an obvious red flag for avalanches, but we could see two naturally triggered slides that were, at most, 48 hours old. Both had started near protruding cliff bands where the rock had conducted heat down into the snowpack, probably creating an unstable layer of depth hoar deep in the snow.

Anyway, the warning signs were there.

Now, I want to go into some of the decision-making of the men, according to the Gazette article.

First, according to the Colorado Avalanche Information Center, there were naturally triggered slides right next to where they descended.

Second, the two were "experienced backcounty climbers who have ascended 50 of the state’s 54 mountains over 14,000 feet." This is an often cited, but essentially meaningless fact. Avalanche danger is counter intuitive. More time in the backcountry does not make a person less likely to be caught. Some studies suggest the opposite.

Third, the father said he didn't think the danger was significant because the snow had not gone through a "melt and freeze cycle." This is completely erroneous. Freezing and thawing does not necessarily increase or decrease avalanche danger. Other factors, such as the temperature gradient within the snowpack, new snow, and wind events are much more important.

Last, and most important. The two didn't go one at a time. They were both sliding down an open slope together. They were both caught in the same slide and both buried. Even if they had worn proper rescue equipment, which they didn't, they wouldn't have been in a good position with both buried. This is a mistake too many people make. If there is even a chance of a slide, go one at a time.

What can we learn from this? Take an avalanche safety class if you are going to be traveling in the backcountry. It may not save your life, but it probably won't hurt.


Anonymous said...

Everybody is always an expert when it doesn't happen to them.

Brendan Leonard said...

"Avalanches don't care that you're an expert." (I don't know who said that.)

merlot maiden said...

"Experienced" backcountry hikers know to carry safety equipment with them, ie transceivers, shovels and poles. Doesn't sound like these guys were carrying anything. Experienced doesn't mean 'smart'.