1.8 - Making Waves

Question 1

How do tsunamis form?

Answer 1

Mega thrust fault/landslide
Displaces column of water
Water radiates outwards from epicentre (800kmh)
Slow down at shallow coast - friction with seabed
Shorter wavelength, higher amplitude (waves catch up and bundle)
TSUNAMI

Question 2

Variables

Answer 2

Distance from source (lose energy over distance)
Offshore bathymetry (shallow/deep)
Coastline orientation (East of Japan)
Shape of coastline (estuaries)
Coastal topography (height)
Fault displacement (water)

Question 3

Speed

Answer 3

Roughly 800 km/h

Question 4

Refraction

Answer 4

Waves refracted around Australia

Question 5

Wave heights

Answer 5

Close to source - really high - 240+cm at Japan
Further from source - lower - 10cm at Australia
Coastlines - higher - 40cm at Loes Angeles