Earthquake examples

Question 1

Asian tsunami (2004)

Answer 1

Subduction of the Indian plate under the Sunda plate and Burma microplate.
:- Indian oceanic plate dips down creating a large thrust fault. Horizontal movement along the fault was 20m.
:- The overlying microplate sprang back, causing the focus to be only 30km deep.
:- vertical displacement meant that the sea floor moved up by 3m, displacing the entire column of water above it.

Question 2

impacts of the tsunami

Answer 2

1. sea water created bores in river channels
2. coral reefs in the Indian ocean were battered by debris like cars being pulled by backwash.
3. thick layer of debris accumulated on top of the water made is difficult for survivors to be seen by rescuers.
4. damage and loss of life was most in Sumatra. The coastal towns were destroyed as building were on wooden stilts.
5. low lying land in sumatra was transformed into shallow sea. in the Maldives, over 1,000 island that were barely 1m above sea level were rendered uninhabitable.
6. in southern India, mangrove areas stopped the force of the waves so coastal areas were protected here.

Question 3

Tohoku, Japan (2011)

Answer 3

• japan is located at the meeting point of the philippines, Eurasian and pacific plates.
• build up of strain energy as pacific plate subducted was eventually released, sending shockwaves and displaced the water above - MEGATHRUST
• destructive boundary with faults running outwards
• magnitude 7.2 on March 9th. 2 days before the 8.9 on 11th.

Question 4

impacts

Answer 4

1. a spine of mountains running down the centre of Japan so people are concentrated in coastal areas, making them vulnerable to the tsunami.
   2.