|
|
Article: Magnetic Field
- Article from:
- World of Earth Science
CopyrightCOPYRIGHT 2003 The Gale Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Magnetic field
Earth acts as though it were a huge dipole magnet with the positive and negative poles near the North and South Poles. This does not mean that Earth is literally a dipole magnet
—
there are too many variations in the field
—
but that the best fit for a model of the field is two poles of a magnet, rather than a quadrupole, or other shape. The magnetic field of the earth allows magnetic compasses to work, making navigation much easier. It also molds the configuration of Van Allen belts, bands of high-energy charged particles around the earth's atmosphere.
Most of Earth's magnetic field (90%) occurs below the surface and possibly exists because Earth's core doesn't ...