(Part Two) Taking note of snow condition reports and recognizing warning signs can go a long way to avoiding being caught in an avalanche. Significant amounts of rain or snowfall can cause the snowpack to become unstable, with avalanches frequently happening on the first sunny day following a storm. Warmer temperatures can result in less stable snowpack as the snow moves down, pulled by gravity. Experts advise snow skiers to listen to the snow, particularly when enjoying a back-country snow sport adventure. Cracking or ‘whumpfing’ sounds are a warning of unstable snowpack, as are hollow bass-drum sounds when traveling over hard snow.
Avalanches most often occur on slopes between 35 and 50 degrees, but are a possibility on any slope steeper than 30 degrees. Skiers should be aware though, that even if the area they are skiing is less than 30 degrees, if there are steeper slopes higher up, there is still the possibility of an avalanche. Common trigger points are along ridge crests where wind-driven snow has collected, near rocky outcrops in the snowpack and areas where there is mid-slope steepening. Cornices in the snow indicate the prevailing direction of the wind and could serve as a sign that the slope below consists of wind-loaded snow. Whether the slope faces the sun or is in the shade is also significant, and skiers should make use of a compass to determine the direction the slope is facing. Some ski areas are known as avalanche zones and even if there are no outward signs, there may be persistent weak layers, and skiers should consult the local avalanche advisory authorities for information relevant to the area.
In the interests of safety, never ski alone and ensure that all members of the group watch out for one another. Preferably ski one one the slope at a time, but if this is not possible, keep well spread out and never descend directly above your ski partner. Bear in mind that an avalanche beacon is invaluable in search and rescue operations.
If an avalanche is heading your way try to ski to the side of the sliding snow, and when it reaches you discard your skis and poles. Grab onto the downhill side of trees if you have the opportunity to do so, or roll onto your back with your feet facing downhill. When you feel the avalanche slowing, try to make airspace around your mouth. If you are completely buried, you will have to rely on rescuers to find you, so try to remain calm until they do.
If your partner is caught in an avalanche there will be no time to go for help, so while watching the victim to establish a last seen point, try to alert others to the emergency situation. While your first instinct may be to rush to your partner’s aid, it’s important to determine whether you will be safe to do so. Look for discarded equipment and/or clothing indicating a possible location. If the victim is wearing a beacon, conduct a beacon search, probing before digging. If there is no beacon to track, probe around the areas where surface clues were found, as well as in possible catchment areas. Keep looking until you find the victim, whose life is in your hands.
Avalanche and first aid training should be a top priority for all back-country skiers, snowboarders, snowmobilers, hikers, mountaineers and any other adventurers who may be heading into snow-laden territory. Being prepared for emergencies will allow snowsport enthusiasts to enjoy their chosen activity with greater peace of mind.
(Part One) Located at the University of Colorado in Boulder, CO, the National Snow and Ice Data Center (NSIDC) promotes research in the Earth’s cryosphere – the portions of our planet where water exists in solid form. This includes lake ice, river ice, sea ice, ice caps, ice sheets, permafrost, glaciers and snow cover, with the latter being of particular interest to snow sport enthusiasts. The NSIDC has grown from its original status as an analog archive and information center tasked with archiving data from the 1957-1958 International Geophysical Year, to the technologically sophisticated data management and scientific research center it is today, with the ability to manage terabytes of data from NASA’s Earth Observing system satellite program, while at the same time gleaning information from the smallest text file relating to the cryosphere.
The NSIDC is intensely interested in areas where ice and snow may impact human populations, and special attention is paid to the dangers of avalanches, with the view to training and preparing people to deal with potentially life-threatening situations. The Colorado Avalanche Center notes that 89 percent of victims are between the ages of 20 and 29, with up to 89 percent being men. The fact that 75 percent of victims are experienced backcountry skiers should come as no surprise, considering the increased risk factor of skiing un-groomed trails. The increase in avalanche fatalities in recent years is attributed primarily to the increase in snow and mountain oriented recreation. Skiing, snowboarding and heli-skiing, as well as hiking and mountaineering in snow covered mountains, attract millions of adventurers every year. To accommodate all the adventure seekers, more roads, towns and resorts are being built in areas prone to naturally released avalanches. The increased activity in the mountains may also result in an increase in avalanches.
Avalanches are known to occur throughout the year, but there are certain times of the year where avalanche activity increases. In the northern hemisphere, the highest number of avalanche fatalities occurs from December through March when snowfall is highest, and when ski areas are at their busiest. May and June records reveal that avalanche incidents increase as summer draws near and snow begins to thaw, or unexpected snowfalls catch recreational skiers by surprise.
Although avalanches are a very real safety issue, being aware of what to look out for may help you avoid this danger, and if you should get caught in an avalanche, knowing what to do can quite literally be a life-saver, for you and your companions. More about this in the next article.