Avalanche - Flateyri - Iceland

Question 1

2 types of avalanche?

Answer 1

slab + powder

Question 2

which type of avalanche is worse?

Answer 2

powder

Question 3

what causes a slab avalanche

Answer 3

partial melt - sheer stress exceeds sheer strength.

Question 4

what causes a powder avalanche

Answer 4

after lots of fresh snowfall. usually larger scale than slab.

Question 5

what defences have been employed in Flateyri to mitigate the impact of avalanches.

Answer 5

• 3 dams, 2 large dams , 1 collecting dam

Question 6

what triggered the construction of the dams?

Answer 6

a 430,000m3 avalanche in 1995 - killed 20 people.

Question 7

what caused the 1995 avalanche?

Answer 7

strong winds.

Question 8

describe the large dams.

Answer 8

600m long, 15-20m high.

Question 9

describe the collecting dam.

Answer 9

10m high, runs between the 2 large dams.

Question 10

what is the capacity of the dams?

Answer 10

700,000m3

Question 11

when were the dams completed?

Answer 11

1998

Question 12

were the dams a success?

Answer 12

yes,

- successfully deflected 2 avalanches. 1999 and 2000, which would have destroyed homes.

Question 13

other methods of reducing the impact of avalanches/controlling avalanches. (4)

Answer 13

1. controlled avalanches - TNT/explosives + ski patrols.
2. Snow fences.
3. Afforestation.
4. prediction + monitoring - snowfall levels/hazard mapping.