Avalanche - Flateyri - Iceland Flashcards Preview

A Level - Geography: CS > Avalanche - Flateyri - Iceland > Flashcards

Flashcards in Avalanche - Flateyri - Iceland Deck (13)
Loading flashcards...
1
Q

2 types of avalanche?

A

slab + powder

2
Q

which type of avalanche is worse?

A

powder

3
Q

what causes a slab avalanche

A

partial melt - sheer stress exceeds sheer strength.

4
Q

what causes a powder avalanche

A

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

5
Q

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

A
  • 3 dams, 2 large dams , 1 collecting dam
6
Q

what triggered the construction of the dams?

A

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

7
Q

what caused the 1995 avalanche?

A

strong winds.

8
Q

describe the large dams.

A

600m long, 15-20m high.

9
Q

describe the collecting dam.

A

10m high, runs between the 2 large dams.

10
Q

what is the capacity of the dams?

A

700,000m3

11
Q

when were the dams completed?

A

1998

12
Q

were the dams a success?

A

yes,

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

13
Q

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

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