Diagram showing the magnetic field that surrounds and penetrates the planet Earth. Magnetic field lines emerge from the south magnetic pole, bend overhead and converge at the north magnetic pole, which is offset from the geographic north pole by 11 degrees. The field, which closely resembles that of a bar magnet, is generated by currents circulating in the interior of the planet. The Earth's magnetic field has a strength at the poles of 60 microtesla (0.6 gauss), nearly 200 times weaker than the field of a domestic fridge magnet. Also indicated are the inner (blue) and outer (mauve) Van Allen radiation belts, layers of charged particles held above the Earth by the magnetic field.