Safe Snow Manual
Safe Snow Manual
The
charm of deep powder snow on virgin slopes induces many skiers and snowboarders,
even at a low skill level, to venture off the regular pistes. Surely a
descent in powder is more charming than the usual ski tracks, which are
often too easy, usually too artificial and always crowded. But the risks
you can find in the mountains shouldn't be forgotten. Avalanches, crevasses,
crests and ice are common and they can transform a great ski day into a
bad day.
It's impossible to eliminate all the risks (every year, even the most expert guides are involved in accidents), but the best strategy isn't to rely on good luck; knowledge of some basic rules can limit the danger and make each decision a calculated risk. Each of us must be able to judge our own limits and where we cross the border into recklessness. I'm not a guide, but I lived in the mountains for much of my time and so I have good experience; I hope this brief guide will help you better understand the mountains and backcountry skiing and travelling.
Remember that the best way to start backcountry travelling is by taking along an expert local guide.
Topics:
Equipment The
Descent Skiing
on the Glacier
Steep
Slopes/Extreme Skiing Avalanches
Bibliography
Generally I prefer skis with these characteristics: 1) not too stiff; 2) possibly lightweight; 4) medium to short length.
As for snowboards, the best choice is a longboard (160-175 cm), large and with a long tip. Boots need to be soft, better for freeriding (freestyle boots are too soft). Bindings must be a two-strip close.
ARVA (Avalanche Victim Researcher (Beacons: PIEPS, ORTOVOX etc)) is a very important, possibly life -saving tool. It's a little box with a battery that emits a signal, so you can be found under the snow if you are unluckly and get caught in an avalanche. There is another kind of tool, the ELP, but it's not as efficent as ARVA because it doesn't emit a signal, only reflects signals from another source.
The Group: Never go off the regular tracks by yourself, because if you have an accident, if you get caught in an avalanche or if you fall in a crevasse, there is nobody to help you or call the rescue service. But it's also best not to ski in too large a group (at most 6-8 persons) because the heavy weight on the slope can cause a snowslide.
Order of Descent: Don't ski too close to the others in your group and always stop before the skier ahead of you (it's possible that he has seen an obstacle, a cliff or a crevass that you haven't seen).
The Track: Avoid long cuts and traverses of a slope. It's better to go down directly without hesitation; if a traverse is necessary it's important to do it as high up as possible, nearer the rocks, so if you start an avalanche you remain on the top. Avoid getting under big crests because of the danger of snow falling from above and sheet avalanches (made by wind). Don't follow the tracks of other skiers if you are not sure where they go.
Precaution: If possible it's a good idea to carry a CB. The cellular telephones are OK, but in the mountains there is not always good communication coverage.
Snow Cover: Throughout the Year: In the first part of winter, even with good snowfalls that cover the crevasses, the temperature is too cold and the snow cover doesn't become strong enough to make safe snowbridges over the cracks. The middle of the winter is the best period because the snow cover is good and the main part of the crevasses are closed, - but always pay attention!
During the spring, the higher temperature and the sun weaken snow bridges, so it's best to remain on the north-facing slopes.
Obviously these considerations can and do change with the weather conditions, the latitude and the elevation.
How to Descend: 1) Maintain a slower speed and look forward. 2) Find the crevasses by looking at the color of the snow cover. 3) Go over snow bridges as fast as possible. 4) Avoid skiing on glaciers with blowing snow, bad visibility or white out.
If you Fall in a Crevasse: Don't get out of your skis or snowboard! - They can stop your fall against the ice walls. If you see someone else falling into a crevasse, and it's impossible to offer help immediately, mark the location and go to call help. It's dangerous to go to the edge of a crevasse alone: if you too fall in, nobody remains to get help.
Steep
Slopes and Extreme Skiing
The concept of steep slopes is a relative concept; a short and wide descent of about 45° with good snow, ending in a flat runout can be easier than an icy and long chute of 30°. The difficulty of a slope varies not only with the skier's ability and preferences; factors like snow conditions, psychological situations and physical conditioning can all affect the difficulty of a track.
Equipment: On extreme pitches, edge grip is very important, so it's better to choose ski a bit longer than a typical alpine ski: you must have more edge in contact with the snow. Short skis can give better control, but not the same safety. The bindings should be set very tight, with a higher DIN level, and it's a good idea to put a bit of glue in the screw hole to perfectly set the binding on the ski board.
For snowboarders it's a must to have soft bindings in powder, but if the slope is really extreme, expecially with ice, hard boots are the right choice. A longer and not too flexible board (alpine) is the right one.
Dangers: Usually avalanches are not so dangerous on the really extreme slopes, because the angle is so steep that the snow sloughs down immediately, without accumulating. Much more dangerous are the steep slopes which never have really fixed cover and so the probability of an avalanche here is always high.
General Advice: On extreme descents, most important are good physical condition and strong conviction. The first turn is always the hardest and you must face it with determination. Fundamental are a thorough knowledge of ski technique, snow conditions and the mountains.
General Advice:
1) A big fall of fresh snow raises the avalanche risk; just 30 centimeters
of fresh powder will make 
most
slopes dangerous.
2) Slope angle is an important factor; the danger zone is in the range of 35° to 55°.
3) Knowledge of the kind of terrain you are skiing is very important. In my opinion the most dangerous ground is the long-grass meadow, because the snow can't bond onto grass and because a some air and water remain under the cover. Smooth rock is also not very safe, because snow can slide down it; best are the gravely slopes, because the snow can cling well to this surface. The safest terrain is wooded areas because the trees block the snow and protect it from the wind.
4) The wind always raises the avalanche risk (slab avalanches).
5) The warm (Fohn) winds greatly increases the risk because they raises the temperature of the snow (heavy snow avalanches).
6) A quick increase of temperature raises the risk of wet and heavy snow avalanches.
7) Always check the avalanche and weather bulletins before you go.
8) Always use an ARVA (avalanche beacon, snow beeper).
Types of Avalanches:
Powder Avalanches: This is most typical after a big snow fall.
It's easy to prevent and, if it's not too big, may not be too dangerous.
The great problems come with the big ones, because the powder can rise
in a very fast wave (up to 160 mph) that can suffocate you. These serious
avalanches are very hard to escape from due to the large front and the
high speed.
Slab Avalanches: These are the most frequent cause of deaths (70-75%) because they are very hard to prevent. The wind makes the slabs; it pushes the snow crystals one on top of the other, to create a large slab; the slab is heavy and not fixed to the surrounding snow so it can start moving at any time. A big danger is that the point of initiation of a crack isn't necessarily where is the skier is, but can be higher, so a skier can get caught by his own avalanche.
Wet Avalanches: This is the typical spring avalanche: the sun and the rising temperature melt the snow, creating a water layer over which snow cover can slide. The danger is primarily because of the weight, but fortunately the speed is generally slow, so it's possible to avoid it. This is a frequent type of avalanche.
Remember that these are only theoretical descriptions of avalanches; usually the real avalanches are a combination of these 'types'.
Weather Knowledge: To have a high level of safety when you decide to do a long and exacting alpinist or ski-alpinist tour, it's good to have some basic meteorological knowledge like: prevailing winds, barometric pressure, temperature, humidity and approaching weather fronts. It's important to read the weather forecasts and expert bulletins, but a basic personal knowledge can be useful in the unpredictable mountain weather system and in difficult situations.
FUORI PISTA by M. Trotin - CDA Torino
GUIDA ALLO SCI FUORI PISTA by L. T. Flores - Zanichelli
LE NEVI DELLE DOLOMITI (ed. 1 e 2) by M. Gallo - Cierre
L'ENIGMA DELLE VALANGHE by K. Fraser - Zanichelli
LA NEVE. EVITARE LE VALANGHE by R. Cresta - Quick
GUIDA AL TEMPO IN MONTAGNA by A. Schneider - Zanichelli
If you would like to ask questions or offer comments or suggestions, you can email me at Alessandro Casson
Have safe fun !
