Unlike most materials we come in contact
with snow is within 95% Kevin (K) of its melting point. To contrast this,
the steal alloys in your car are within roughly 18% K of their melting
point. Molecules in the snow pack are, there for, very mobile and
subject to change. The layer of snow out side your door may appear
static and unchanging throughout the winter, when in fact, the snow reacts
quickly and easily to atmospheric changes (temperature and relative humidity).
The changes snow undergoes once it’s
on the ground can either make the snow pack more stable (less likely to
avalanche) or weaker (more likely to avalanche)
A more useful property of snow for
the understanding avalanche formations is the way in which snow deforms.
Snow can react bridaley or plastically, much like a glob of silly pudy,
depending on the rate of the applied load. When a large load is
applied to the snow pack in a short period of time it can break (brittle
reaction) much like an over stretched rubber band. Appling the same
load over a longer period of time can result in the snow pack slowly sagging
and deforming.
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