How do avalanches happen?
In 90 percent of avalanche fatalities, the avalanche is
triggered by the weight of the victim, or someone in the victim's
party. Natural avalanches occur because new or windblown snow
overloads weak layers of snow, or because of rapid warming, but
there's almost always obvious signs of instability by the time
avalanches come down on their own.
Here are more opinions and answers from other s users:
- When too much snow builds up, and there is too much vibration,
an avalanche occurs.
- They happen by vibration.
- An avalanche is a natural process in which snow responds to the
pull of gravity.
- When snow falls, its own weight causes it to melt and refreeze,
therefore bonding the crystals together. This is how a glacier is
formed. But, if the climate is unusually warm, or the snow has no
time to melt, the bond is weak. This area of weak snow is very
unstable. When a skier yells, or when a person is just too heavy,
he displaces a small amount of snow. This causes (mind the pun) a
"snow ball effect". One ounce of weak snow moves. This allows
another few ounces to move, which in turn, causes the whole area of
weak snow to start falling down the mountain. All this happens
verry quickly, but can be prevented.