How to read the mantle
Part of Hall of Planet Earth.
The globe in the center shows present-day mantle convection based on studies of how tectonic plates have moved over the last 200 million years. These motions reveal where the mantle is rising and sinking. This snapshot agrees with data from the seismic, or shock, waves generated by earthquakes and explosions traveling through Earth.
The Churning Core
Convection also occurs in the liquid iron-nickel alloy of the outer core. The swirling metal carries an electric current and creates a magnetic field called the magnetosphere, which has poles similar to a bar magnet. The magnetosphere shield Earth from harmful cosmic rays.