What you should do to prepare yourself
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
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.
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
[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
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
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.
[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
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?
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
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
[Mountain Zone Home]
(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.)