Earth has a diameter of 12,756 km (7,972 mi). The earth's interior consists of rock and metal. It is made up of four main layers:
1) the inner core: a solid metal made up of nickel and iron (1200 km diameter)
2) the outer core: a liquid molten
core of nickel and iron
3) the mantle: dense and mostly solid silicate rock
4) the crust: thin silicate rock material
The temperature increases rapidly up to 9000 F in the core. Therefore, the intense heat from the inner core causes material in the molten outer core and mantle to move around. As a result, the large plates on the earth's crust slowly drift on the surface. It is also possible that these currents generate the earth's magnetic field, called the magnetosphere.
