Tectonic Plates

Crust ~ solid rock 5-50km deep, split up into plates.

Mantle ~ molten rock with slow-moving currents, 2900km thick.

Outer Core ~ liquid metals, 2200km thick.

Inner Core ~ solid metals, 2500km wide.

The earth's hot core heats up the magma

As it is heated it gets lighter and rises

Near the surface it cools and gets heavier (it sinks!)

The convection curants move the magma which causes the plates to move about

Oceanic Crust:

• Newer - most less than 200million years old
• Denser
• Can sink
• Can be renewed or destoyed

Continental Crust:

• Older - most over 1500million year old
• Less dense
• Cannot sink
• Cannot be renewed or destroyed

Where two tectonic plates meet is called a Plate Boundary. This is where volcanoes and fold mountains are formed, and is also where earthquakes and tsnamis often happen.