Like earthquakes, they occur on plate boundaries where plates rub against each other or one plate is pushed under another.

There are 3 main types of earthquakes:

Active - They can erupt at any time.

Dormant - They have not erupted recently (within the last 2000 years).

Extinct - They will not erupt again.

Although earthquakes cause deaths and there are man reasons not to live near earthquakes (on plate boundaries) there are advantages such as the soil is often fertile.

Case studies:
Below is an example of a volcano - click on it to visit the case study:
<CS!> Mount St Helens

Click here for GCSE coursework essays on Volcanoes