Earthquakes and tsunamis

Question 1

What are tsunamis, and what are they caused by?

Answer 1

Large waves caused by the displacement of large volumes of water

Question 2

What can trigger tsunamis and why?

Answer 2

Underwater earthquakes, volcanic eruptions and landslides, because they cause movement of the sea floor and displace large volumes of water. Waves will then radiate out from the epicentre/area of displacement

Question 3

How will the tsunami be affected by movement of the sea floor?

Answer 3

Greater the movement of the sea floor, the greater the volume of water displaced, and the bigger the wave produced

Question 4

Why will a tsunami be more powerful it it starts close to the coast?

Answer 4

The waves lose energy as they travel towards land. So the close the waves start to land, the less energy they will lose

Question 5

How can tsunamis cause a high death toll?

Answer 5

Waves travel very fast in deep water, so they can hit the shore without much warning