Plate Tectonics. By Lydia Pillinger. Plate tectonics. The Earth's surface is made up of a series of large plates. These plates are in constant motion travelling at a few centimetres per year. The ocean floors are continually moving, spreading from the centre and sinking at the edges.
By Lydia Pillinger
When the earths plates pull apart causing magma to rise to surface. They can also occur when one plate dives beneath another, this also causes magma to rise to the surface. This is known as the subduction zone
Where do volcanoes occur?
They usually occur on the edges of the plates, near where earthquakes occur. Volcanoes occur around the edge of the pacific ocean called the ring of fire.