2 Hazards

The dangers which the craft of climbing has been developed to avoid are of two main kinds: the danger of things falling on the traveller and the danger of the climber falling himself. The things that may fall are rocks, ice and snow; the mountaineer may fall from rocks, ice or snow, or into crevasses in ice or snow. There are also dangers from weather. Thus in all there are eight chief dangers: falling rocks, falling ice, snow-avalanches, falls from difficult rocks, falls from ice slopes, falls down snow slopes, falls into crevasses, dangers from weather. To select and follow a route avoiding these dangers is to exercise the climber's craft.

2.1 Falling Rocks

Every rock mountain is falling to pieces, the process being especially rapid above the snow-line. Rock-faces are constantly swept by falling stones, which it is generally possible to dodge. Falling rocks tend to form furrows in a mountam face, and these furrows ( couloir s) have to be ascended with caution, their sides being often safe when the middle is stoneswept. Rocks fall more frequently on some days than on others, according to the recent weather. Local experience is a valuable help on such a question. The direction of the dip of rock strata often determines whether a particular face is safe or dangerous; the character of the rock must also be considered. Where stones fall frequently debris will be found below, whilst on snow slopes falling stones cut furrows visible from a great distance. In planning an ascent of a new peak such traces must be looked for. When falling stones get mixed in considerable quantity with slushy snow or water a mud avalanche is formed (common in the Himalaya). It is vital to avoid camping in their possible line of fall.

2.2 Falling Ice

The places where ice may fall can always be determined beforehand. It falls in the broken parts of glaciers (seracs) and from overhanging cornices formed on the crests of narrow ridges. Large icicles are often formed on steep rockfaces, and these fall frequently in fine weather following cold and stormy days. They have to be avoided like falling stones. Seracs are slow in formation, and slow in arriving (by glacier motion) at a condition of unstable equilibrium. They generally fall in or just after the hottest part of the day, and their debris seldom goes far. A skilful and experienced ice-man will usually devise a safe route through a most intricate ice-fall, but such places should be avoided in the afternoon of a hot day. Hanging glaciers (i.e. glaciers perched on steep slopes) often discharge themselves over steep rock-faces, the snout breaking off at intervals. They can always be detected by their debris below. Their track should be avoided.

2.3 Snow Avalanches

The avalanche is the most underestimated risk in the mountains. People generally think that they will be able to recognise any risks. The truth is a somewhat different story. 120 - 150 people die in small avalanches every year in the alps alone. The vast majority are reasonably experienced male skiers aged 20-35 but also include ski instructors and guides. There is always a lot of pressure to risk a snow crossing. Turning back takes a lot of extra time and effort and most importantly there seldom is an avalanche to prove the right decision was made. Making the decision to turn around is especially hard if others are crossing the slope.

There are two types of avalanches;

1. The slab avalanche: This type of avalanche occurs when a plate of snow breaks loose and starts sliding down.
2. The powder avalanche: This type of avalanche is triggered by a small amount of moving snow that accumulates into a big slide

When going off-piste or travelling in alpine terrain parties have a moral responsibility to always carry:

1. avalanche beacon
2. probe
3. shovel (retrieving victims with a shovel instead of your hands is five times faster)

and have had avalanche training!

2.4 Falls from Rocks

The skill of a rock-climber is shown by his choice of handhold and foothold, and his adhesion to those he has chosen. Much depends on a correct estimate of the firmness of the rock where weight is to be thrown upon it. Many loose rocks are quite firm enough to bear a person's weight, but experience is needed to know which can be trusted, and skill is required in transferring the weight to them without jerking. On all difficult rocks the rope is the greatest safeguard for all except the first climber in the ascent and the last in the descent. In such places a party of three or four individuals roped together, with a distance of 15 to 20 ft. between one and another, will be able to hold up one of their number (except the top man) if one only moves at a time and the others are firmly placed and keep the rope tight between them, so that a falling individual may be arrested before his velocity has been. accelerated. In very difficult places help may be obtained by throwing a loose rope round a projection above and pulling on it; this method is especially valuable in a difficult descent. The rope usually employed is a strong Manila cord called Alpine Club rope, but some prefer a thinner double rope. On rotten rocks the rope must be handled with special care, lest it should start loose stones on to the heads of those below. Similar care must be given to handholds and footholds, for the same reason. When a horizontal traverse has to be made across very difficult rocks, a dangerous situation may arise unless at both ends of the traverse there be firm positions. Even then the end men gain little from the rope. Mutual assistance on hard rocks takes all manner of forms: two, or even three, men climbing on one anothers shoulders, or using for foothold an ice axe propped up by others. The great principle is that of co-operation, all the members of the party climbing with reference to the others, and not as independent units; each when moving must know what the man in front and the man behind are doing. After bad weather steep rocks are often found covered with a veneer of ice ( verglas), which may even render them inaccessible. Crampons are useful on such occasions.

2.5 Ice Slopes

Crampons are also most useful on ice or hard snow, as by them step-cutting can sometimes be avoided, and the footing at all times rendered more secure. True ice slopes are rare in Europe, though common in tropical mountains, where newly-fallen snow quickly thaws on the surface and becomes sodden below, so that the next night's frost turns the whole into a mass of solid ice. An ice slope can only be surmounted by step-cutting. For this an ice axe is needed, the common form being a small pick-axe on the end of a pole as long as from the elbow of a man to the ground. This pole is used also as a walking-stick, and is furnished with a spike at the foot.

2.6 Snow Slopes

Snow slopes are very common, and usually easy to ascend. At the foot of a snow or ice slope is generally a big crevasse, called a bergschrund, where the final slope of the mountain rises from a snow-field or glacier. Such bergschrunds are generally too wide to be strided, and must be crossed by a snow bridge, which needs careful testing and a painstaking use of the rope. A steep snow slope in bad condition may be dangerous, as the whole body of snow may start as an avalanche. Such slopes are less dangerous if ascended directly than obliquely, for an oblique or horizontal track cuts them across and facilitates movement of the mass. New snow lying on ice is especially dangerous. Experience is needful for deciding on the advisability of advancing over snow in doubtful condition. Snow on rocks is usually rotten unless it be thick; snow on snow is likely to be sound. A day or two of fine weather will usually bring new snow into sound condition. Snow cannot lie at a very steep angle, though it often deceives the eye as to its slope. Snow slopes seldom exceed 40°. Ice slopes may be much steeper. Snow slopes in early morning are usually hard and safe, but the same in the afternoon are quite soft and possibly dangerous; hence the advantage of an early start.

2.7 Crevasses

Crevasses are the slits or deep chasms formed in the substance of a glacier as it passes over an uneven bed. They may be open or hidden. In the lower part of a glacier the crevasses are open. Above the snow-line they are frequently hidden by arched-over accumulations of winter snow. The detection of hidden crevasses requires care and experience. After a fresh fall of snow they can only be detected by sounding with the pole of the ice axe, or by looking to right and left where the open extension of a partially hidden crevasse may be obvious. The safeguard against accident is the rope, and no one should ever cross a snow-covered glacier unless roped to one, or even better to two companions.

2.8 Weather

The primary dangers caused by bad weather centre around the changes it causes in snow and rock conditions, making movement suddenly much more arduous and hazardous than under normal circumstances. Whiteouts make it difficult to retrace a route while rain may prevent taking the easiest line only determined as such under dry conditions. In a storm the mountaineer who uses a compass for guidance has a great advantage over a merely empirical observer. In large snow-fields it is, of course, easier to go wrong than on rocks, but intelligence and experience are the best guides in safely navigating objective hazards.

Summer thunderstorms may produce intense lightning which are attracted to the highest points on the ground. If a climber happens to be standing on or near the summit, they may now in fact be the highest point. There are many cases where people have been struck by lighting while climbing mountains. In most mountainous regions, local storms develop by late morning and early afternoon. Many climbers will often begin ascents "alpine style"; that is before or by first light so as to be on the way down when storms are intensifying in activity and lightning and other weather hazards are a distinct threat to safety.

3 See also

• Ski mountaineering
• Glossary of climbing terms
• List of climbing topics
• Peak bagging

4 Reference

• This article incorporates text from the public domain 1911 Encyclopaedia Britannica. Please update as needed.

Mountaineering

<Hide>