If you've ever heard the terrifying rumbling of an avalanche you won't be surprised that avalanches can travel at speeds of up to 300 km per hour (almost 200 mph), measure up to 100 metres high (over 300 feet) and weigh millions of tonnes. In most cases, it is impossible to out ski them, outrun them, or even get away fast enough on a skimobile. Avalanches are so powerful that their velocity can tear trees from their roots, flatten buildings, and destroy anything in their path. What chance does a mere human on skis stand against such a force of nature? When we plan our skiing trips we take out travel insurance, pay a little extra for the winter sports coverage, and then tend to forget about the potential dangers of being in the mountains.

The sad fact is that if you see an avalanche thundering down towards you, you may well have triggered it in the first place! If you are an avid off-piste skier or boarder, the best you can do is to be prepared in case you find yourself caught in one. You're much more likely to be involved in an accident while travelling to or from your ski destination than caught in an avalanche - but that's little consolation for avalanche victims and their families.

There are many myths about avalanches. Despite what you might see in Hollywood movies, avalanches are not triggered by shouting but they can be triggered by the sound waves of explosions at close range. Another myth is that you should spit if buried in an avalanche to find out which way is up. Even if you are able to spit, it won't do you much good if you're buried deeply because the snow around you will be as solid as a wall. You won't be able to move let alone dig yourself out - unless you are lucky enough to have landed close to the surface.

The amount of survival equipment you choose to carry is a personal decision and it's a good idea to check for any new inventions or recommendations online or at your favorite outdoor or ski shop before setting off. The three basic pieces of emergency equipment (at the time of writing) usually include a folding shovel, a probe, and a transceiver, You may well be lucky enough to survive an avalanche, but if it takes rescuers a long time to locate you then your chances of survival will diminish as the clock ticks away. There are more advanced pieces of equipment on the market, such as special vests to assist with breathing, or the old standbys like avalanche cords.

A transceiver (transmitter/receiver), also known as a beacon, EPIRB, or GPS, is strapped to your body and emits a signal which could mean the difference between life and death in locating a victim and digging them out. A GPS mobile phone might also be of use in alerting emergency services. A special lightweight shovel works better than skis, ski poles or anything else when trying to dig through several feet of snow. A probe is a thin pole which can be assembled into a longer pole and used to find those buried in the snow.

Most deaths from avalanches are not caused by their impact but by suffocation (asphyxia) or by hitting rocks, trees, or other hard objects during the fall. Suffocation is caused by breathing your own exhaled carbon dioxide in a confined airspace. Other common causes of fatalities in avalanches are hypothermia and serious physical injuries such as fractures of the neck or ribs.

There are hundreds of avalanches in the Alps, in North America and Canada and throughout the world each year. They are often triggered by climbers, snowmobilers and off piste skiers. Even with an experienced guide along, the dangers of skiing off piste or onto glaciers cannot always be foreseen, but you'll have a better chance of staying out of trouble.

Each year there are reports of skiers buried in avalanches and falling into crevasses. Being stuck in a crevasse could seriously mess up your apr's ski fun! All ski resorts post warnings regarding weather conditions, avalanche risks, and off-piste skiing. It is your responsibility to check these warnings before setting off because failing to do so may invalidate your travel insurance and winter sports cover if the worst should happen.