Flashcards in Avalanches And Management Deck (9):
What is an avalanche?
A rapid downhill movement of snow ice and rocks usually in a mountainous environment
They move down hill at speeds up to 300 km an hour
What are the physical causes of an avalanche?
Heavy snowfall (addition of weight to slope makes it unstable)
Heavy rainfall (lubricates the slope making movement easier)
Steep slopes (pull of gravity will overcome the strength of snow to stay on slope)
What are the human causes of avalanches?
Tree removal (trees keep snow in place)
Skiing and Loud noises both create vibrations which can unsettle snow
When did Les Deux Alls avalanche take place?
What were the trigger of Les Deux Alps avalanche?
Heavy snowfall plus skiing on a closed run were the triggers
What happened at Les Deux Alps?
skiing on a closed black run resulted in the death of two school children and one adult
How do controlled explosions help reduce the avalanche hazard?
Used to trigger small avalanches that have little impact rather than allowing snow to build up to a dangerous level
How does afforestation help reduce the avalanche hazard?
Trees help trap snow on slopes and slow down the movement however this is an unpopular approach in ski resorts