Detecting Earthquakes

Question 1

Explain how data from seismometer can be used to identify the location of an earthquake.

Answer 1

P waves arrive first because they travel faster than S waves.
The time arrival between the different waves can be used to work out how far away from a seismometer an earthquake occurred.
Data from 3 or more seismometers can be used to work out the location of the epicentre, or point where the earthquake originated.

Question 2

How is the earths outermost layer composed of tectonic plates?

Answer 2

It is in relative motion due to convection currents in the mantle

Question 3

What can happen at plate boundaries?

Answer 3

Plates may slide past each other, sometimes causing earthquakes

Question 4

Why do scientists find it difficult to predict earthquakes and tsunami waves with available data?

Answer 4

Because the p waves and S waves come in at different times.

It is not possible to measure the forces trying to move the plates or friction between them