Avalanches – How to Examine the Snow – Part 3/4

In the first part of this avalanche articles series I discussed about the basics and the behavior of an avalanche. In the second part I discussed how to avoid an avalanche. In this third part of the series I dig into the most interesting part, examining the snow. This is an important skill to have up in the mountains and backcountries.

Examining snow during avalanche risk analysis is a very important step

The best way of finding out the avalanche risks is examining the snow profile using a snowpit. You can use a snow shovel, a snowboard and the tail of your ski. It should be approximately 30 inches (75 cm) wide and as deep as possible. Naturally it should be on the same slope you are planning to ski. Clear the sides in order to see the structure of the snow. Then start examining the snow.

Examining the snow profile step by step

First prod the snow every few centimeters with your bare finger. Try to get an idea of any hard and soft layers in the snow. By examining like this, you are looking for radical changes in the snow profile. If the area is safe for skiing, the snow profile should not have radical changes. Instead the profile should change gradually.

Next examine the snow crystals of the layers. Look for radical changes in their sizes or shapes. Look at the water content of each layer as well. If you discover wet layers and free running water, it is a clear mark of a danger, because free running water acts like a lubricant for the snow above. If you are able to reach the ground, check it as well. Rocks are good at keeping snow, but on grass or smooth rock snow can slide much easier due to less friction.

Finally by using your skis dig two channels (30-50 cm apart) in the back of the pit. Stamp down the snow between the channels. If the slab slides away, it is a clear mark that the same might happen if you ski on the area.

There are also other ways to examine the snow, but these ones mentioned above are the “good old” ways to examine the snow profile. If you know other ways to examine the snow or you have good experiences, please share your thoughts with us by leaving a comment.

Test-skiing the slope in order to analyze avalanche risks

Now as you how to examine the snow profile, you can perform one more check before you ski the slope. The last check is called “test-ski”, which simply means that you ski a small area as a test. For test-skiing a slope you need help from your fellow skier who must be familiar with mountain equipment and anchoring. Both of you need glacier equipment, such as harnesses, rope and anchoring devices. If you are not familiar with these equipment and you are heading to backcountries, I strongly recommend you to spend some time with mountaineering and mountain equipment before entering the slopes. It is important to know how to anchor yourself of steep snow, rocks or ice, as well as how to help your buddy out of a crevasse or how to abseil down a rock.

When you test-ski a slope, your buddy needs to anchor him/herself on rock, snow or tree for example. Then you set bind a rope in your harness and your buddy makes sure you won’t be caught by the avalanche if the snow starts sliding. Next ski normally few dozens of meters until there is no more rope left. Then look at your tracks and the snow around you. Are there cracks? Has the snow started sliding? If there is nothing suspecting and your other checks have been ok, it looks like the slope is risky. In this phase you need to decide whether you will ski the slope or not.

For more about avalanches, see the homepage of Avalanche.Org. There is a lot of great information on avalanches!

In the last part of this article series we will discuss about skiing the slope and acting in case of emergency.

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