Tsunamis

Question 1

1. Tsunami

Answer 1

On a plate boundary between the Eurasian and Indo-Australian plate

Question 2

2. Tsunami

Answer 2

Destructive (subduction occurs) and tension builds over many years

Question 3

3. Tsunami

Answer 3

An 9.1 earthquake occurs and water displaced 30km^3 upwards above the epicentre. This sucks water back from the coast, and can be the only sign a tsunami is about to hit - water column displacement.

Question 4

4. Tsunami

Answer 4

In deep water, the waves are low and fast and as the waves approach shallow water they slow, due to increased friction.

Question 5

6. Tsunami

Answer 5

Waves spread out from the epicentre across the Indian Ocean and affect 12 countries

Question 6

7. Tsunami

Answer 6

20-30 m waves break onto the coastline and the 4th or 5th wave is usually the biggest and most powerful

Question 7

What was the magnitude and focus of the Indian Ocean tsunami?

Answer 7

9.1 and 30km

Question 8

Where was the epicentre of the tsunami?

Answer 8

155km from Sumatra

Question 9

When do the waves hit Sumatra?

Answer 9

15 mins after the earthquake

Question 10

What is a tsunami?

Answer 10

A special type of wave where the entire depth of the sea or ocean in set in motion by an event, often an earthquake, which displaces the water above it and creates a huge wave

Question 11

What are the primary and secondary effects of a tsunami?

Answer 11

The crust shifting, the displacement of water above the moving crust: this is the start of a tsunami

Question 12

5. Tsunami

Answer 12

They also grow taller because of the shallower water and converge together, which increases the energy of each wave.