Mantle Facts

  • The mantle makes up the bulk of the Earth’s interior. It reaches from about 10-90 km to 2890 km down.
  • As you move through the mantle temperatures climb steadily, until they reach 3000°C.
  • Mantle rock is so warm that it churns slowly round like very, very thick treacle boiling on a stove. This movement is known as mantle convection currents.
  • Mantle rock moves about 10,000 times more slowly than the hour hand on a kitchen clock. Cooler mantle rock takes about 200 million years to sink all the way to the core.
  • Near the surface, mantle rock may melt into floods of magma. These may gush through the upper layers like oil that is being squeezed from a sponge.
  • The boundary between the mantle and the core (see Earth’s interior) is called the core–mantle boundary (CMB).
  • The CMB is about 250 km thick. It is an even more dramatic change than between the ground and the air.
  • Temperatures jump by 1500°C at the CMB.
  • The difference in density between the core and the mantle at the CMB is twice as great as the difference between air and rock.
  • Scientists have found ‘anti-continents’ on the CMB that match with continents on the surface.