Wednesday, February 12, 2014
Avoiding and Surviving Avalanches
It's the time of year when we go out to play in the snow. We slip into snow pants, and take out our skis and snowboards and hit the slopes or hike and snowshoe into the mountains for beautiful icy views. On the steep slopes of hills and mountains though, no matter what activity we are engaging on, there is one danger we all have to be careful of. Avalanches.
Avalanches are a giant mas of snow, ice, and rocks that descend rapidly down the side of a slope. Generally these slopes are going to be the side of a mountain, but could also be a large hill as well. No matter what type of slope though, avalanches can come without warning, and if you find yourself caught in one, it could be deadly as well.
Common sense is your best defense against finding yourself in potentially deadly situations. When it comes to avalanches there are a few simple things you can do and look for to help keep yourself out of harms way.
1. Don't Hike Right Away
Experts recommend waiting at least forty eight hours after a snowfall before going out on a slope. This is because most avalanches occur during or just after a snowfall. When snow falls, it adds more weight on already existing snow, however bonds between the old snowfall and the new snowfall is weak. The combination of weak bonds and added weight leads to a situation where snow can start to slide, and if it does that are you are on the slope below, you could find yourself buried in snow.
2. Hike the Ridgeline
Where you climb on a slope is important. You want to hike on the windward side of a slope, where snow is thinner. Hiking along a ridgeline gives you the ability to see where the snow is and where you want to walk. What you want to avoid is wave shaped drifts that form on the lee sides of ridges. A build up of windswept snow will react similar to a fresh snowfall, and therefore, just like new snow, it will be more unstable.
3. Watch the Trees
On snowy slopes trees can be your best friend. Numerous trees, especially older more mature trees will anchor snow to the slope, in the same way the anchor dirt. They can also provide a blocking force against avalanches, disrupting the slide of snow down the mountain. Traveling in or below mature trees is always a safer way to travel across snowy slopes.
The trees can also give you an idea of how common avalanches are in the area. If branches and trees at the top of a forested area are broken, then this can be an indication of recent avalanches.
4. Look Up
If you are going to be doing activities in the mountains during snowy months, you need to learn a little about slope angles. Avalanches happen on slopes, not on flat ground. The gentler the slope, the less risk of an avalanche happening. However remember less likely does not mean that it will not happen.
What you want to look out for are slopes with a twenty five degree angle or more. The steeper the angle, the more likely it is for snow to start to slide, and an avalanche to start. Thirty to forty five degree angled slopes are the most likely to experience an avalanche.
You also want to look at the shape of a slope. If the middle of the slope bows inward, then the slope is likely to be more stable because the snow underneath will help support the snow pressing down on the sides. Meanwhile a slope that has more of a dome shape across its width will be less stable.
5. Cross High
Similar to hiking a ridgeline, if you need to cross a steep slope, you should cross high on a slope rather than low. It won't necessarily put you out of harms way, but if there is an avalanche and you get caught in it, you will caught towards the top of the avalanche. People who are caught at the top of an avalanche are more likely to survive because they tend to stay towards the surface of the sliding debris.
6. Carry the Correct Equipment
Never rely on technology first. You should always know your survival techniques because they don't require batteries. However when you are going out on the mountains during these winter months you should be bringing equipment with you, which can help you get yourself and others out of an avalanche, as well as help others find you in an avalanche. Make sure before you go out that all your equipment is working, and that you know how to use it all.
So what happens if you've done everything you can to avoid avalanches but find yourself in the middle of one anyway? The first thing to do when you hear the telltale rumblings of the beginning of an avalanche is to alert anyone around you to the danger. From there if you can get out the path of the avalanche, then do so.
If there is no chance of getting out of the way then drop any equipment you are carrying. Then find anything that might help protect you from the snow. Crouch behind a tree or rock, and turn away from the slide.
If you are swept away by the snow then mimic swimming to help keep you further up near or above the surface of the snow. Keep doing this until you feel the snow beginning to slow.
When trapped in an avalanche this is perhaps the most crucial moments where you really have to act. You will only have around three seconds to move before the snow sets. There are three very important things to do in these few seconds:
1. Stand up. This way you are closer the surface and closer to potential rescuers.
2. Put your arms in front of your face. Make sure to place your elbows out to create an air pocket in front of your face. Also take a huge breath and hold it to give your chest room to move.
3. At the last second punch an arm towards the surface. Doing it at the last second leaves your air pocket intact, while also getting your arm hopefully above the surface of the snow to help rescuers find you.
Once the snow has settled you will have to assess your situation. If the snow has settled loosely then you may have some mobility. In this case you should start to dig upwards. If you don't know which way up is then just spit. Gravity will pull the spit down no matter which way you are facing. This will give you a direction to dig.
If you can't move, stay calm. Don't try to move too much and yell only when rescuers are close. This will conserve oxygen so that you limited air supply lasts longer, until your rescuers arrive.
So as we continue through these winter months go out and enjoy the snow, just make sure you are being safe while doing it, and if disaster strikes, make sure you are prepared to deal with it. Happy snow days everyone!