Table of Contents
For Students
Discover
Observations of the magnetic field of Earth’s surface indicate that more than 90 percent of this field arises from sources internal to the planet. A variety of mechanisms for generating this field have been proposed, but at present only the geomagnetic dynamo is seriously considered. In the dynamo mechanism, fluid motion in the core moves conducting material across an existing magnetic field and creates an electric current. This current produces a magnetic field that also interacts with the fluid motion to create a secondary magnetic field with the same orientation as the original field. The two fields together are stronger ...(100 of 14820 words)