Charged metals passing through these fields go on to create electric
currents of their own. This self-sustaining
loop is known as the geodynamo.The spiralling caused by the
Coriolis force means that separate magnetic fields created are aligned in the same direction, so both effect adding up to
produce one vast magnetic field around the entire the planet.
This magnet is the inner core. The inner core of the earth is made iron allowing it to have magnetic qualities. BTW, this is physical science. Just thought to let you know.
