Every year in Alaska as fall fades into winter recreaters and explorers
prepare their equipment for another season of winter fun. High in the
hills some something else is being prepared though. As the snow
depth increases from centimeters to meters a deadly crystalline structure
is forming. These “weak layers” that often develop in the snow pack
can lay dormant for weeks or even months waiting for something or some one
to tip the critical balance between strength and strain in the snow pack.
All too often the trigger is a backcountry traveler and year after year
the death toll in Alaska rises.
How can a soft fluffy slope of new snow shatter like a pane of glass,
and turn in to a river a frozen ice crystals? Before we can investigate
how slab avalanches are triggered we must first gain an understanding
of how snow acts as a material and how slab avalanches form.