Snow Cover
  Whenever traveling in avalanche country it is important to be aware of your environment.  Steep gullies and wide plains are perfect paths for avalanches.  Ridges and unconformities in the terrain may help to slow down an avalanches speed.  The severity of an avalanche is directly related to the terrain in which it happens.

    One of the most important factors to consider is the slope of the mountain or hill.  Most avalanches occur between 20 and 50 degrees like the diagram above shows.  However, the largest avalanches occur between 30 and 45 degrees, and the areas which have the greatest frequency of avalanches are between 35 and 40 degrees.  This is due to the fact that this angle allows the most snow to collect at the least stable angle.

      Another important feature to consider when working or playing in places where avalanches are a definite possibility are anchors. Anchors are features of the terrain which hold the snow in one place.  A good example is the picture below on the left.  The route with many trees is labeled "best route" because the trees help hold the snow in place.  Although an avalanche could still go through this area, the trees would slow it down, if not stop it.  Also an avalanche is less likely to start in a densely forested area.


    Another essential anchor to look for when choosing your path are rocky areas.  Rocks, like trees, help hold the snow in place.  Obviously an avalanche probably won't start on a rocky area.  However, if an avalanche is coming down the mountain, it will take the path of least resistance meaning that a rocky ridge will probably be avoided by the avalanche.  The picture above to the right illustrates the path an avalanche would probably take.
Slab Avalanches
Cornices & Ice
Slope Stability

Created by Sarah Schlichting for Physics 212
Last modified 04-04-03