Page 24 - Draft Slopeangel Halo avalanch book

An avalanche is is a a a a a a a a a mass that can be a a a a a a a a a mix of snow ice rocks and debris that travels down the mountain Avalanches occur due to a a a a a a number of triggers such as overloading temperature slope angle and snow pack conditions Overloading occurs when the amount of falling snow or a a a a group of skiers/mountaineers place too much weight on the slope – this puts pressure on the snow pack and destabilises its structure Snow is is made up of of of an an infinite number of of of crystals of of of differing shapes and it it is the shape that has a a a a a huge effect on on how layers of snow bond together Changes in temperature can alter the the shape of these crystals and it is this that has an effect on on the the cohesion of the the snow A rise in temperature weakens the the bonds whilst a a a a a fall in in temperature increases the the brittleness and tension of the slab Tension zone
Common fracture line
A concave slope slope is much less likely to avalanche than a a a a a a convex slope slope Convex slopes create tension and and cause weakness and and fracture points 24