Avalanche on Nuptse
Avalanche on Nuptse, near Everest
photo: Todd Burleson

see also
Skiing Home
Snowboarding Home
Everest '98
News Index:
many stories about avalanches including Avalanche kills snowboarder
Avalanche on Mt Rainier
Mauduit killed by avalanche
Boukreev swept away by avalanche

Avalanche Safety
What you should do to prepare yourself

Mark Twight on Rainier
Mark Twight,
Mt. Rainier
[click to zoom]
photo: Paul Baugher
What should you know about avalanches?
Before the ski areas even opened this season, a group of five snowboarders, eager to get first tracks, hiked to the legendary Baldy chutes at Alta, Utah. Four members had already ridden down and were waiting for the last member of their group to join them. This would never happen. As he began his fateful descent, he triggered the avalanche that would partially bury his companions and take his life.

And now into February, it seems like not a day passes without news of an avalanche disaster, whether in the Sierra Nevada of California, the backcountry areas of the Pacific Northwest or in Chamonix, France, where chalets were leveled by the rumbling beast and many lost their lives.

Almost as quickly as the avalanche debris begins to settle, the process of introspection begins. How did this happen? I know the mountains are inherently dangerous but how could this happen to me? What can I do to feel better about my backcountry trips this winter? The conventional avalanche wisdom says, "There are no rules of thumb." The new wisdom holds that avalanche accidents don't happen due to bizarre quirks of fate. There is a particular set of physical and human factors that underlie each accident. There is a lot of knowledge that you can acquire about the factors that result in avalanche accidents. It starts with some basic awareness.

"The most important of all the statistics is that once a victim is completely buried, there is only a 1 out of 3 chance of survival..."

Who gets caught and where does it happen?
Avalanche statistics tell us about the nature of the beast. Most accidents involve slab avalanches. The victim, or a member of the victim's party, usually triggers the slab that kills them. About 85% of the avalanche fatalities happen in the backcountry. Skiers and climbers make up the bulk of the numbers. However, snowmobilers and snowboarders are surpassing the old guard at an alarming rate.

Slab Avalanche Crown
Slab Avalanche Crown
[click to zoom]
photo: Northwest Avalanche Institute
Last year, the snowmobile category alone accounted for almost half of the fatal accidents in North America. What you do and where you do it become important as you learn about avalanche hazard. The profile of the accident can vary with time of season and place. In Montana, a snowmobiler, with little or no avalanche awareness, may release a dry slab avalanche, while "high marking" in midwinter. By spring, we may see an experienced climber on a northwest volcano, knocked off of a steep slope by a small loose snow avalanche. Not only do you need to be aware of local snow and weather factors, but also of what particular hazards you face, based on your statistical profile.

Where do I begin?
Start by arming yourself with a solid understanding of the fundamentals. Avalanche conditions form as a result of the interaction of terrain, weather, and snowpack. All of the information we use to predict snow stability is in this triangle. Learn to recognize the subtleties of avalanche terrain. Most mountain travelers can spot the obvious paths. But learning to anticipate where on a particular slope that a fracture will occur, and how far it may propagate, takes some study. Learn to pay attention to the weather. Storms are the source of most the world's avalanches. The combination of new snowfall and wind creates the unstable layering that result in slab avalanches. Simply put, during a storm, the rate at which stress is added to the snowpack exceeds the rate at which these new layers can gain strength.

"About 85% of the avalanche fatalities happen in the backcountry. Skiers and climbers make up the bulk of the numbers..."
Recognize weather patterns. A prolonged period of cold and clear weather can substantially weaken the snowpack. This can set up a hair trigger situation. Learn to "feel" the snow. Once you have a good grasp of the physical processes that determine the layering of the snowpack you can begin to "feel" the snow. Qualities like the stiffness or styro-foam texture of the snowcover are significant. Hollow sounds, cracking, or collapsing are also important field observations. As each clue is observed, they need to be related to the processes at work. You need the ability to explain why cracking of the snow surface local to your ski tracks may be quite benign in one case and lethal in another? Your ability to "feel" the snow may be quite limited, unless you carry the knowledge of slab structure and fracture propagation, into the field with you. This base of knowledge allows you to evaluate the stability of a given slope.

What do I do in the field?
When you are travelling in avalanche terrain you must always have an opinion about snow stability. Since snow stability varies dramatically with time and space, your opinion should constantly be revised. New observations will either support or refute your opinion. It is important that you seek out the most relevant data. A snow pit or a Rutschblock test may yield valuable information. However, if when you step out of the ski track to dig your pit, and the slope settles a few inches, you may have all the data you need. The route you choose must be based on your stability evaluation. You may decide to minimize your exposure to avalanche terrain or you may actively seek it out. Just remember that timing is everything, when travelling on steep and deep powder slopes. Some days you can go anywhere, some days just south slopes, and some days you need to stay in the flatter terrain.

Slab avalanche
Slab Avalanche
[click to zoom]
photo: Northwest Avalanche Institute
Also, remember that avalanche hazard is relative to where you are. How much of a slide is required to knock you off of a steep stance or take you into a crevasse? What do I do before crossing a slope? First, you must determine whether you are in terrain capable of producing avalanches. That is terrain recognition. Next, determine whether the snowpack is currently capable of producing avalanches. That is stability evaluation. Then you must ask yourself, if it slides, what will happen to me, and is there a better alternative route? This is hazard evaluation and route selection. The key is to be very flexible and willing to change your plans. Avalanche professionals practice safe travel techniques, as a ritual, not selectively. This has compensated for the occasional error in stability evaluation.

What else should I consider?
Unfortunately, there is more to it than just understanding the physical characteristics of avalanches. We must learn to recognize the traps that affect our decision-making in the mountains. The human factors that bias our decisions range from a high risk tolerance to complacency. Beware of the false sense of security we get from a blue sky day, a strong group, or a set of tracks already in the path. Consider the case of an experienced trip leader who has traveled the same route many times, often during marginal conditions, without incident. That lack of evidence of avalanching is often misinterpreted as stability. This negative feedback is found in many accidents. We must be constantly alert to this trap. We must seek out the real data like the slope angle and recent weather. Perhaps the most insidious trap of all is the pressure to proceed in the face of unstable conditions. The desire to reach a summit or the fear of being late for work has little to do with hazard evaluation. Unfortunately, the root of a lot of accidents can be traced to this type of decision-making pressure.

What if I make a mistake?
"The conventional avalanche wisdom says, "There are no rules of thumb." The new wisdom holds that avalanche accidents don't happen due to bizarre quirks of fate..."
It can be valuable to conduct a rescue drill early in an avalanche training course. This allows students to witness the difficulty and confusion first hand. Once everyone has concluded that avalanche rescue is a marginal option at best, learning how to avoid being caught takes on a new importance. The most important of all the statistics is that once a victim is completely buried, there is only a 1 out of 3 chance of survival. The next number that works against you is the length of burial. A speedy location and recovery of the buried victim is essential as the survival rate drops to 50% after 20 minutes. Carrying and knowing how to use rescue equipment is essential. The newest of the hi-tech rescue beacons is of limited value without routine search practice or a shovel. Travelling with well trained and properly equipped companions may be comforting, but it does not compensate for a flawed or careless stability evaluation.

Where can I get help?
You need formal training. Look for a course that is taught by avalanche professionals. You could learn the technique for a Rutschblock test in almost any avalanche course. However, learning to correctly interpret the results takes an instructor with years of forecasting experience. Ask if the curriculum follows the guidelines for level I and II courses established by the American Association of Avalanche Professionals (406) 587-3830. If it has been some time since your last formal training you are probably due for some continuing education. Remember that there are no shortcuts to a good avalanche education. You can get help with your homework before you go. Before each trip listen to the avalanche forecast. Most of the mountain areas in the western US and Canada have avalanche forecast centers. One example, the Northwest Avalanche Center, (206) 526-6677, issues bulletins throughout the winter. By connecting to this site you can link to most other warning centers. It is important to note that some of these centers, like the Northwest Avalanche Center, are chronically under-funded and at risk of closure. It may be in your best interest to support your local avalanche center.

Be careful of planning your trip by the calendar. Just because it is May 31 and a blue sky day doesn't mean you leave the beacon, shovel, and probe behind.

Paul Baugher, Mountain Zone Correspondent
(Paul Baugher is the director of the Northwest Avalanche Institute (360) 825-9261 which conducts training programs in the western U.S., ranging from basic avalanche hazard evaluation, to courses for professionals. Paul has been a professional avalanche forecaster for 20 years. His responsibilities include being the ski patrol director at Crystal Mountain, vice president of the American Association of Avalanche Professionals, and instructing at the National Avalanche School. Paul and his partner Eric Simonson operate Mount Rainier Alpine Guides.)

[Mountain Zone Marketplace] [Mountain Zone Home]