TO BECOME A MOUNTAINEER ONE MUST NOT ONLY LEARN TO CLIMB; ONE MUST ALSO LEARN TO UNDERSTAND MOUNTAINS. - BY GASTON REBUFFAT

I HAVE ALWAYS BELIEVED THAT THE BIGGEST HAZARD ON THE HILL IS THE PERSON WHO DOES NOT KNOW, HAS NOT CONSIDERED, OR CANNOT BE BOTHERED TO FIND OUT BASIC PRINCIPLES OF MOUNTAIN SAFETY. - BY KEVIN WALKER

• Generally speaking, the higher you climb, the colder it will become. The rate of change of temperature with altitude is known as Lapse Rate.
• In certain circumstances the valleys can be colder than the tops due to Temperature / Ground Inversion occurs when dense cold air flows down from the mountains. The mildest is Frost Hollows (pockets of cold air) - as much as 5°C lower than mountain slopes. The more serious form is when cold air sinks and trapped in the valley bottom, it can be several hundred meters thick.
• Cold temperatures potentially causing mountain Hypothermia, numb and Frost-bite.
• Hot temperatures may cause Heat exhaustion and Heat stroke. An advise is to wear a sun-hat, a good sunscreen (do not underestimate its value), and drink more liquid.
• A tragic accident occurred in Snowdonia - on a warm spring day, a young hill walker reached a mountain lake, did not realise that the water, having so recently been snow, was only few degrees above freezing. Whilst he was extremely hot and sticky, stripped off and dived in. The shock of entering icy water was so great that it killed him.

• Cloud can cause poor visibility. Eg. Stratus cloud can have its base below 300 meters and, if it is raining, the cloud may be thousands of meter thick.
• Hence lessen enjoyment by the lack of extensive views, and also make navigation hard.
• Cloud which hugs the mountains is often known as hill fog. Ground-level clouds are known as mist. Mountains can also make clouds by forcing air to rise.
• Cloud is formed from water droplets, therefore it will make rocks wet (slippery) and people wet (get cold).
• Cloud can form rime (a feathery white ice which coats rocks) if the temperature drops below freezing point.

• Mountains make their own rain. They form a barrier to the wind, force air to rise, causing it to cool and lose some of its moisture. This moisture can condense either as cloud or as rain. Any such rain is known as Orographic rain.
• Mountain barriers can physically slow down fronts, causing Cyclonic rain to last far longer than it would be otherwise be the case.
• Frequency of rain increased in mountain areas because both Orographic and Cyclonic rainfall occur, when the two occur at the same time, or when turbulence causes mist droplets to join together to form rain, the intensity of the rain is increased (heavier).
• In heavy rain, routes which follow gullies or grooves can become impassable. Exceptionally heavy rain can cause landslides on steep mountain slopes, and may cause rocks fall in gullies. River crossing will also become more hazardous than usual.

• There are 3 main potential hazards which are directly related to the electrical activity in lightning. These are Direct strikes, Ground currents, and Induced currents.
• During thunderstorm (which is caused by electrical activity in atmosphere), the clouds become so highly charged with electricity that they ionise the air around them to allow the electricity to arc to earth.
• Just before the main lightning flash, a small spark known as Leader move relatively slowly through the air, ionising as it goes, and forms a channel of conduction along which the main spark can travel at speeds of up to 1 hundred times faster.
• Lightning does not always strike the most prominent features; it often strikes the weathered boundary between 2 beds (or layers) of rock, because these usually contain moisture and mineral deposits which make them excellent conductors.
• When the lightning reaches the ground, the electricity is now in the form of Ground currents, follows the line of least resistance and will therefore concentrate its attentions on damp crack and moist gullies, using up its energy as it goes further.
• Metal items do not actually attract lightning, but they can have electricity currents induced in them when in the immediate vicinity of a strike. These Induced currents usually are of little danger, but they are not if combined with Ground currents.
• Current which passes form 1 hand to another is extremely dangerous because it will pass through the hearts and lungs. Most serious is a current which passes from head to foot as in a Direct strike, because it affect almost every organ in the body. Whereas it is possible to survive a current which passes from 1 foot to another through the legs.

• Hail is always associated with Cumulonimbus clouds and often falls during thunderstorm.
• The stones themselves are formed when water droplets are caught in the turbulence of a rapidly ascending air current. As they rise, they freeze and continue to grow as more water vapour freezes on their surface. Eventually they become too large to be supported by the air current, and so they fall, often still growing on the descent.
• Majority of hailstones are spherical with a diameter of slightly over 5 millimeters. Walking into hailstones can be an extremely painful exercise, and some of stones can have edges which are sharp enough to cut when driven by a strong wind.

• When wind reaches the mountains, the same amount of air has to pass through a small place, it therefore increases speed in much the same way as water going over a weir.
• Wind increases its speed when forced through a valley in the same way as water flowing through a sluice gate.
• If for some reason the air cannot rise above mountain, it may flow around it like water flowing around an island, causing the wind speed to increase across the shoulders of the peak.

• If wind blows across a series of ridges, it can generate a strong waves, it can become extremely turbulent and form a Rotor, which can cause sudden, strong and totally unexpected gusts in the opposite direction to that of the main wind. Rotor can be fatal.
• Walk against wind requires greater physical effort. A freezing winter wind or a dust-laden summer wind can bring tears to the eyes. Snow-goggles or sun-glasses may help.
• Increase in wind speed will act in exactly the same way as a decrease in temperature, especially in wet condition. This effect is known as Windchill (when air moves, it will increase its cooling effect). Windchill is a term commonly used when talking about mountain Hypothermia as Windchill temperature can be well below freezing.

• Snow is formed from tiny ice crystals when atmospheric water vapour is subjected to sub-zero temperatures and freezes.
• When it is very cold, snow will falls as individual crystals. When it falls through a Temperature Inversion, it may partially melt and then be refrozen resembling soft hailstones.
• On reaching air with a temperature above freezing point, the snowflakes will slowly melt and become sleet. Sleet continues to fall and eventually turning into rain.
• If snows falls in misty conditions when there is already snow on the ground, it will cause a white out.
• Blizzard is a severe snow storm and strong wind occur together.
• You could die in a blizzard with sheer fury of the wind, the numbing, paralysing cold, the snow which felt like sand, hurting, rasping, and almost impossible to breathe.
• The only one wise way to cope with blizzard is to retreat before it gets too bad.

• The higher one climbs, the greater the reduction in atmospheric pressure, and the less oxygen there is to breathe. The air expands because of this reduction in pressure and, as a direct consequence, it cools.
• The rate of cooling with increased height is known as Lapse Rate. The value of Lapse Rate is not constant, but varies with the water content of the air, generally it can be between 1°C to 3°C per 300 meters.
• Generally, on windy day or when the air is particularly dry, the Lapse Rate is higher, and conversely, if air is saturated as it will be in clouds, it drops.
• The cooler the air, the less water vapour it can hold, when rising parcels of air become saturated, it is said to have reached the dew point. Any further cooling and increase in altitude will result in water vapour condensing, when this happens, the water droplets so formed will either create clouds or, if clouds are already present, they may form drizzle or rain.
• Finally, high winds increase the Lapse Rate as well as the Windchill effect.

• Conservation of energy is one of the prime requirements of good mountaincraft. Besides, keep a steady and rhythmic pace.
• Steep ground causes fall especially when it is slippery or rocky.
• If the slope becomes so steep that it is necessary to use your hands, you have entered the realm of Scrambling, and you probably find the rock-climbing skills come into useful.
• For walking in the steep ice or snow, find out the technique of using rope, ice-axe, crampons and others.

• The most common cause of stonefall is Freeze-thaw Action. Hence, the most hazardous time to walk below cliff is after a very cold night, just after the sun is beginning to melt any ice. Also, the likelihood of stonefall is dramatically increased during thunder.
• During spring, when the rocks which have been held in place throughout the winter by snow or ice are suddenly set free. The loose rocks so formed either remain on ledges until dislodged (usually by climbers), or fall down the cliff and pile up the bottom, eventually forming sizeable slopes of loose rocks known as scree.
• Some scree slopes are dead, while others are active and still growing. Active scree can be recognised by its relative lack of vegetation and the profusion of loose rocks, many of which will be the same size.
• When walking through scree slopes, any loss of balance could send loose rocks down on your companions and might result in a nasty fall, where rocks are fairly small and uniform, hence you might find it easier to Scree Run. Generally speaking, the shorter your step, the better.
• If you do dislodge a stone, wherever on the hill, make sure you give warning shout - ‘stone !’ to the climbers below at the top of your voice.

• Never cross a stream at night or when it is in spate. Either you make a detour to find a bridge or safe crossing point, or wait until the water level drops.
• When you have made the decision to cross, firstly, take off your socks and trousers. This reduces drag and also means you have dry clothes after crossing. However, you must wear your boots.
• Secondly, close your rucksack as tightly as possible so that air is trapped inside to act as buoyancy should you be swept away. However, be cause the buoyancy will be on your back, so it might push you face down in the water, so release the hip belt before you cross, be prepared to slip the rucksack from your shoulders, and hold it across your chest.

• A cornice is an overhanging mass of snow, formed at the top of certain slopes by the action of the wind.
• Cornices may collapse as you walk above them or below them especially during a thaw, in or immediately after snowstorm, or when there have recently been winds strong enough to drift the local snow.
• Cornice can forms a dangerous barrier which guard the end of the climb. Although it can be overcome by cutting a slot, tunnelling up or breaking through it by removing some of its snow, the job is extremely strenuous and may further weaken the cornice that leads to collapse.

• Snowflakes are unstable and will change their shape over a period of time, this change is known as Metamorphism.
• During Destructive Metamorphism, the original crystal structure of flake is changed, individual crystals become simplified and freeze together, forming a strong bond. Thereby reducing the risk of avalanche.
• When temperature hovers around 0°C, freeze-melt Metamorphism can occur to form different snow layers often separated by definite junctions. During the day, when temperature may rise above freezing, melt water flows along the junction forming a lubricant along which upper layers may slide.
• Constructive Metamorphism can occur if temperatures remain well below freezing point for any length of time. Under these circumstances, the surface layers can be far colder than those close to ground, and water vapour will rise through the layers and may re-crystallise, the process resulting in large unbonded crystals of depth hoar (or sugar snow). These will form a weak layer which, in addition to acting as a lubricant, may suddenly fail and cause a Climax Avalanche.
• During a thaw, when temperature rises so quickly that the crystalline structure is destroyed before the snow melts. This will in a loss of cohesion which will cause the snow to flow down the nearest slope, and it is called Wet Avalanche.
• Powder Avalanche occur during extremely cold dry weather, or if there are sudden heavy snowfalls after a cold spell or on to a solid crust, it travel in high speed as fast as 45m/second and normally accompanied by and intense shock wave.
• There are 2 types of Slab Avalanches caused by wind-slabs : Soft Slab -formed by winds with speeds not exceeding 50km/h; Hard Slab - formed by winds with speeds greater than 50km/h.
• Avalanches can only occur if there is sufficient snow and 80% of them occur during or immediately after heavy snowfalls.
• Avalanche can potentially occur on any slopes of between 20° and 60°, and the most dangerous are those between 30° and 45°.
• However, there comes a point beyond which the angle is so great that snow cannot accumulate enough because it will begin to move slowly downhill under the influence of gravity, and so the risk decreases.
• If buried by avalanche, you must make yourself an air space as near to the surface as possible and quickly, as snow may set solid within a few seconds of stopping. Remember that the air you trap will have to last until someone rescue you. The deeper you are buried, the less likely you are to survive.

6. CREVASSE

• The greatest danger of glacier travel is fall into a crevasse. Many of crevasses are hidden, they are deep, cold, scary and may kill.
• Crevasse are most dangerous in the Accumulation Zone, that portion of a glacier high enough to receive more snow every year than it losses to melting. Here, crevasses are frequently covered with snow, either filling the hole or forming bridges over the void.
• If you are on the glacier, it is a continuous game of Find the Crevasse. Just because you can’t see them does not mean they are not there. What appeared to be small cracks may be gaping chasms, and major crevasse may have been hidden from the angle of your view.