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Magnetic field overview

The geomagnetic field protects the Earth's atmosphere against charged particles from the solar wind. Rapid and long-term changes in the field are monitored by low-orbiting satellites and a global network of about 200 magnetic observatories. Field models, computed from these measurements, provide the direction and strength of the magnetic field at any desired location. Magnetometers (or a simple compass) can then be used to compute pointing directions, complementing the location information provided by the global positioning system (GPS).

The primary contributions to the geomagnetic field are

For animations showing the change of the main magnetic field over the past centuries:

Last modified: Wednesday, 10-Nov-2010 10:22:11 MST