Before starting work on this topic it is vital that you know the structure of the earth, as it underpins a majority of the work related to natural hazards. The diagram below summarises the most important points:

Place the cursor over the various sections of the earth to see what they are called:

Crust

• Thin, outer-layer of the earth.
• It is as thin as the skin of an apple is to its flesh.

Mantle

• Composed mainly of silicate rocks, which contain a lot of magnesium and iron.
• It extends to a depth of 2900km.
• Temperatures can reach 5000 degrees Celsius, which generate convection currents.

Core

• Contains iron and nickel.
• Situated approximately 6371km below the surface.
• Temperature is around 5500 degrees Celsius.