earthquakes and volcanoes

What are the main parts of the earth?

Give two or three reasons an earthquake occur?

Name and describe the three kinds of faults?

Is the earth's surface constantly changing?

Places where the plates meet are called:

Where do earthquakes take place?

Waves of energy are sent from where?

(a)  

The point on the surface directly above the focus is called the

When P and S waves reach the surface of the earth, they produce what type of waves?

(a)  

What machine is used to detect, time and measure the movements of the earth?

(a)