In this diagram, the red lines represent the edges of the tectonic plates that make up the Earth's crust. For example, iron is mined from the Earth's crust in quarries. It is a finite resource ...

Researchers are now trying to understand the "innermost inner core" of the Earth by studying how seismic waves travel through the Earth.

When an electric current passes through a metal wire, a magnetic field forms around that wire (see diagram at right ... and generators to operate. In the Earth (see image below right), the ...