13. formation of tsunami

Question 1

1.

Answer 1

tsunami waves start when seismic energy from offshore EQ forces out mass of sea water

Question 2

2.

Answer 2

tsunami waves start at height of less than 1m, wavelengths of 100 - 150 km at speeds 800km/h may pass

Question 3

3.

Answer 3

reaching shallow water –> greater friction (against land) –> slows waves & forces increase in height

Question 4

4.

Answer 4

tsunami waves travelling at 30 - 50km/h may reach heights around 15m

Question 5

5.

Answer 5

sea recedes from coast before advancing –> water rushes to fill void caused by movements of sea floor –> water forced outwards, resulting in tsunamis