The Earth has four layers and they are as follows:
- Crust: the surface of the Earth.
- Mantle: beneath the crust. The mantle consists of the upper mantle & the lower mantle. In the lower mantle pressure & heat make rock flow slowly.
- Outer Core: made mostly of liquid iron & nickel. The outer core is 2,200 km thick.
- Inner Core: the deepest layer of the earth. The inner core is made of solid iron & nickel. 1,200 km thick.
