Avalanches Flashcards
1
Q
avalanche defintion
A
falling masses of snow that can contain rock, soil or ice
2
Q
trigger factors of avalanches
A
- sudden increase in temperature
- heavy rainfall can lubricate the slopes
- long cold dry winter
- as warm atlantic air meets cold polar air there is a heavy spring snowfall
- vibrations caused by off-piste skiing or heavy traffic
- deforestation
3
Q
what year was the Galtur avalanche?
A
feb 1999
4
Q
powder avalanche
A
fine grained snow that behaves like gas. very destructive
5
Q
physical factors
A
high levels of snowfall in preceding days
6
Q
social impacts
A
- 31 deaths
- houses buried
7
Q
environmental impacts
A
- concrete buildings flattened
- crushed cars
8
Q
short term responses
A
- outside help couldn’t reach town at first as main road was blocked by an earlier avalanche and bad weather prevented helicopters flying in
- residents dug out 20 people
- a few days later helicopters brought fruit, vegetables and other food into Galtur, returning with survivors and toruists
9
Q
long term responses
A
-$20 million spent on avalanche protection structures
10
Q
Hard engineering techniques
A
- planting trees and building snow fences deflect avalanches away from buildings
- avalanche gully
- deflector to split the flow of the avalanche
- breaking or retardant mounds
11
Q
soft engineering
A
- closing avalanche prone slopes, issuing warnings and daily monitoring
- trigger artificial small avalanches under controlled conditions
