Avalanches are the biggest threat to any person on a slope. While all hills try to groom their runs to avoid the threat of an avalanche, they can still happen especially if you are not riding on a groomed run. While the danger is extremely high in the event of an avalanche, there is a fairly good chance that you will survive if you know what to do and are equipped for it.
The biggest mistake that most people make is that they underestimate an avalanche. An avalanche of dry snow can move at speeds of up to 120 mph thus making it impossible to out run and you may not be able to escape to the sides either due to the tree line or lack of reaction time. While an avalanche may start off with light fluffy snow, it very quickly changes. The momentum of the snow gives it great power, so much so that avalanches commonly snap trees in half, move rocks and cars and can easily crush you against other debris or leave you stranded on the tops of trees.
The danger doesn’t end with debris. The moving snow is rubbing against itself and the terrain thus creating friction. The friction created melts the snow and ice slightly thus creating the second biggest problem. When you finally stop moving the snow will be compacted around you be the weight of the snow still sliding down the hill and then will rapidly refreeze leaving you cemented inside the avalanche. You will not be able to move and will suffocate very quickly unless you are lucky and prepared.
The first and most important thing to staying alive is to never snowboard alone. If you are caught in an avalanche the only way you are going to get out is if someone else digs you out. The more people who are with you the greater the odds are for everyone to survive if there is a disaster.
The next most important thing is to have the proper gear and mindset. Everyone should have an avalanche transponder that sends and receives a signal that makes it easier to locate a buried person. If you are found in 15 minutes there is a 90% chance that you will survive and only a 50% chance of your survival after 30 minutes.
Another thing that you should have is a portable snow shovel and probing staff. There are many types of lightweight shovels that are easy to pack, and useful of other things such as sitting upon and resting your portable stove on when cooking on day trips. A probing staff is pushed into the snow to help feel for anyone buried below you. When using a probing staff it is important to move in a consistent and even pattern starting from the last place the missing person was seen.
Another important point is knowing what causes an avalanche. An avalanche can occur when any one of the following things is true: the angle of the slope exceeds 38′, one of the layers of snow is weak perhaps do to weather and sudden changes in temperature. While snow is not stable on slopes more than 38′, an avalanche can be triggered by events on slopes well below the steep parts or on slopes as low as 25′. Always look up and think about the snow pack. The snow on the hill isn’t a single mass of snow. Each time is snows or the weather gets warm another layer of the snow pack is created. If one layer isn’t stable than all the snow on top of it can slide off as a single sheet and thus trigger an avalanche. Snow packs are stable when the temperature is consistent and changes gradually. Sudden changes in temperature destabilize that snow thus making avalanches more likely.
While an avalanche can surprise anyone, you can greatly reduce the risks by being prepared and thinking about your surroundings. Many people admit that they know better than to ride where they where before an avalanche but didn’t listen to their gut feelings. Do not make this mistake and be prepared in case of problem and you are sure to stay safe even when exploring new areas.