Volcanoes

Volcanoes have been in the news a lot recently, one volcano in particular located in Iceland at the Eyjafjallajökull glacier, which brought Europe's air travel to a halt. But what is a volcano? I'm going to try and explain them, but don't forget I'm not a volcanologist. Volcanology is the study of volcanoes.

The first thing you have to understand is the structure of the earth, there are three layers:

1. The Crust: The crust is the outer layer of Earth. It is made up of plates about 18 miles thick, these plates sometimes move. It is the bit we live on.
2. The Mantle: The second layer is called the mantle. It is about 1,800 miles thick.
3. The Core: The inner layer is called the core.

Between the Earth's crust and the mantle is a substance called magma which is made of rock and gases. When plates on the surface collide, one plate slides on top of the other, the one beneath is pushed down. Magma is squeezed up between the plates.