Getting stuck in an avalanche is one of those terrifying scenarios we hope we never have to experience. Avalanches can happen to experienced skiers, climbers and novice hikers alike, so if you find yourself trapped by one, it’s an unfortunate case of "being in the wrong place at the wrong time".
Avalanches are one of nature’s most powerful forces, and occur in all mountainous regions of the world, where high altitude creates the conditions for overlying snow. They usually occur on slopes of between 30 and 40 degrees elevation, and within 24 hours of snowfall (Wiseman, 1999).
Despite these natural pitfalls, there are ways to reduce the risk of being caught by an avalanche, and some key things you can do if you find yourself stuck in the resultant snowdrift.
Preparation and precautions for trekking in avalanche risk areas
Areas to avoid
Trekking or skiing in mountainous environments requires careful planning of your route, both prior to and during the expedition. Clearly, the best way to avoid being stuck in an avalanche is to avoid danger areas, and know what signs to look for.
The main areas of danger are 1) Snow-covered convex slopes, 2) Lee or dry sides of slopes where snow has accumulated and 3) Deep snow-filled gullies (Wiseman, 1999).
The best areas to stick to are irregular or timbered slopes, which are likely to be more stable and less likely to create an avalanche. Also, the heat of the sun can cause avalanches, so before noon it is a good idea to travel in shaded areas, and keep out of those in the sun (Wiseman, 1999).
Equipment and survival techniques
When embarking on any trip to a potential avalanche risk area it is a good idea to inform the relevant authorities of where you are going, and when you are likely to be back. If you do not return they will have an approximate area to begin their search.
As well as the obvious staples such as, food, water, torch and spare batteries, Global Positioning Satellite (GPS), maps of the area and medical supplies, there is some other vital equipment you will need.
1) Bright coloured jacket and/or rucksack
Wearing a bright coloured or fluorescent jacket and/or rucksack is a good idea, as bright colours can be seen for miles against the white backdrop of the snow. Tearing a piece of your coat or rucksack and tying it to a long straight tree branch or ski pole, can create a good marker for your position. Alternatively, constructing a letter 'I' shape from tree branches (and any available debris), of around 40ft in length by 10ft wide, will signal to any rescuers that medical attention is needed (Wiseman, 1999).
2) Avalanche Transceiver
If you know you will be in an area where avalanches are likely, wear an avalanche transceiver. This relatively new piece of technology for the consumer market is similar in size and appearance to traditional GPS devices, and will help other members of your party, or rescuers find you quickly thanks to its beacon signal.
After being covered by an avalanche the device will begin emitting a distress signal, cutting drastically the time taken to find you, which could be the difference between life and death. Rescuers or other members of the party then place a probe in the ground that can pinpoint the location of the trapped person. Most mountain rescue services now carry the equipment as standard, so taking one along with you on your trek makes good sense.
3) Ice pick or folding shovel.
If you are caught in an avalanche it is unlikely you will have the composure or room to use a pick or shovel to dig your way out. Instead these tools will be used to construct a temporary shelter, such as a snow trench or snow cave, until you are rescued.
To build a snow trench, mark out an area the size of a sleeping bag, and cut blocks of around 18 X 20inches, with a saw blade or shovel. Next dig down at least two feet (this is the minimum depth to shelter you from the wind. Along the edges of the trench, cut a ledge six inches wide and deep, and place the snow blocks on top, leaning them against each other to form a roof (Wiseman, 1999).
Alternatively, if you are in a forested area, cut branches of firs and prop them together to form a roof. Fir branches can also be used as a good insulation for you to sleep on. Another way of keeping in the heat is to dig a cold air gutter beneath your sleeping surface. This will allow cold air to permeate beneath and escape out the other side, which will maintain a warmer temperature throughout the night (Grylls, 2007).
How do you get out of an avalanche?
If the worst happens, and despite avoiding all the possible danger spots you are caught in avalanche, don’t panic. This is easier said than done, but staying calm in any crisis is essential in increasing your life expectancy and thus your chances of survival.
Suffocation is the main cause of fatality in avalanches so getting to the surface as soon as possible is crucial.
Getting out of the snow
If you survive the avalanche you will be extremely lucky and very disoriented. The priority is to determine which way is up, to do this you should spit.
Gravity dictates that all liquids, including saliva, will flow downwards. Therefore if your spit falls back onto your face you are facing the surface and can start to dig in front of your face. If the spit does not hit your face then you are facing the earth and need to dig in the opposite direction. If you have an avalanche transceiver this will also alert any rescuers to your position, so help should arrive soon.
How to survive after an avalanche
Make a fire
After you surface from the snow try to make a fire. Making a fire will keep you warm, cook any food you can catch or already have, melt snowballs for a constant supply of drinking water, and act as a signal to alert rescue services.
To make a fire, collect any loose branches and position them in a 'tepee' shape, and edge with stones or other branches. Next use a processed flint with a saw striker to ensure a reliable spark to ignite the fire (Grylls, 2007). Add small branches to the fire at regular intervals to maintain a steady blaze.
If you have alerted rescuers then stay warm by the fire but get up and move around at regular intervals to encourage circulation. If you are alone, then construct a snow shelter as soon as possible and take shelter for the night. In the morning, if you are able, and are not seriously hurt, try to make your way back to your starting point, and find a road, track or pass which is the best chance of finding people, and thus help.
To avoid further avalanches:
• When travelling after noon, stay on slopes that have already been exposed to the sun, avoiding nay that are now in the sun for the first time.
• Avoid small gullies and valleys with steep with steep side walls.
• Always look out for avalanche activity, even if you don’t see them occur. Try to guess where avalanches started and determine their direction, and how long ago they took place. This will serve as a guide to where other avalanches are likely to occur (Wiseman, 1999)
Grylls, B. (2007). Born Survivor: Bear Grylls. Channel Four Books.
Wiseman, J. (1999). SAS Survival Guide. Harper Collins Publishers, Glasgow.