The facts and figures of avalanche fatalities
Posted by Global Administrator on Sat, Nov 21, 2009 @ 02:38 PM
By Doug Chabot
This year, snowfall in the first days of October here in Montana brought out famished skiers drooling for powder. A two-foot snowstorm resulted in lots of powder turns, a rash of base welds and, of course, a few bumps and bruises.
But fortunately, no fatalities.
While the sunny slopes might bring a few black-and-blue marks, the real dark side of skiing is tragedy from avalanches. People die in slides they trigger. Here are the numbers:
Overall, 94 percent of fatal avalanches were triggered by the victim or someone in their party. Avalanches rarely kill uninvolved bystanders. As skiers, our fate is in our own hands.
In the United States, 284 people died in avalanches over the last ten winters, and an average of 179 people per year were caught in them. The records paint a picture of the typical avalanche victim: Ninety percent are men, with most of them aged 25-29 years old. Women account for ten percent of the fatalities. The majority of them, however inexplicably, are between 40-44 years old.
Most strikingly, the majority of avalanche victims are competent and experienced winter travelers. Three-fourths of them have some type of formal avalanche education. We know that education saves lives, yet it also has a nasty edge by falsely boosting self-confidence. It takes a humble, self-reflective person to keep his or her hubris in check. Accident investigations reveal that peoples’ training lag behind their activity skill levels. In other words, their hunger for steep lines and deep powder exceeded their knowledge of avalanches.
THE SPECIFICS
Avalanche accidents happen mostly in the backcountry. In the U.S. there’s a growing trend to access the backcountry through developed ski resorts. An astonishing 52 percent of skiing and snowboarding accidents happen within two miles of these developed areas, although it’s unclear how many were using lifts at the resort. Regardless, side-country terrain has concentrated tracks from heavy use. Ease of access and limited gear (no skins or touring bindings) seduces folks lacking the necessary backcountry travel skills into serious avalanche terrain.
Ninety-five percent of fatal avalanches are slab avalanches, which have a tendency to fracture once a person is well onto the slope. Slabs break like a pane of glass, all at once, offering limited or no chance of escape. Most fatal slides are small to medium size, with 53 percent of the fatalities from slides less than 20 feet wide and 1,000 feet vertical.
The survival of someone completely buried in an avalanche is far from guaranteed, even with a beacon. Time is the enemy. Within 15 minutes, a victim who is uninjured has a 90 percent chance of surviving, but the chances plummet fast. By 30 minutes the victim’s probability of living are 50 percent -- no better odds than a coin toss, and at 45 minutes they drop to 25 percent.
Both skiers and snowmobilers need faith in their partners’ skill at using an avalanche beacon, but even the newest and simplest models require practice. A study of recreational skiers
found that if two people are buried, one with a beacon and the other without, the person with the beacon only has a 10 percent greater chance of surviving because the average time to find someone was more than 30 minutes. A beacon in the hands of an avalanche professional and others who regularly practice, was definitely better but far from encouraging. In addition to suffocation, avalanches can cause life threatening and fatal injuries by hitting trees, rocks and falling off cliffs. Approximately 25 percent of avalanche deaths stemmed from massive injuries.
CONCLUSIONS
Avalanche victims usually trigger the avalanche that kills them. Of those completely buried, more die than live. Only 34 percent will ultimately survive. But partners who know how to use a beacon, practice with it and carry a sturdy shovel and probe can push the chance of living to over 50 percent.
Even more important than gear is avalanche education. With education and practice we can learn more about avoiding dangerous terrain. Avalanches are all about timing, so evaluating when it’s safe to ski or snowmobile a particular slope is essential. Yet we need to be careful since a little knowledge can fool us into thinking we’re smarter than we really are.
Note: Most of these statistics were gathered by Dale Atkins through data from the Colorado Avalanche Information Center.