Granular depth hoar
acts like a layer of ball bearings beneath the sheet of frozen crust.
One way of determining the risk of avalanche in any given spot is to dig pits and look for telltale signs of weak layers, such as so-called depth hoar
and surface hoar--freezer-burn-like frost that occurs when snow vaporizes and recrystallizes.
Mountain-top trees shrouded in cold clouds become bottom of every avalanche is depth hoar
, snow recrystallized into a lovely, but perilously weak, honeycomb structure.
7 Grainy, sugarlike depth hoar
crystals will slide and take all the above layers with them if their weak bonds break apart.