The mechanism by which the earth's magnetic field is generated, believed to resemble a self-exciting dynamo and to involve circulatory and convective motions and electrical currents within the earth's liquid outer core.
Origin
1960s. From geo- + dynamo.
Definition of geodynamo in US English:
geodynamo
noun
Geology
The mechanism by which the earth's magnetic field is generated, believed to resemble a self-exciting dynamo and to involve circulatory and convective motions and electrical currents within the earth's liquid outer core.