Definition
Geomagnetic field. Nearly dipolar magnetic field emerging from the Earth’s interior.
Dynamo process. Conversion of kinetic energy of motions into magnetic energy.
Geodynamo. Dynamo process operating in the Earth’s liquid outer core.
Introduction
The forces exerted by magnetized rocks or lodestones have been known to mankind for many centuries before Christ, but the directivity of the lodestone appears to have been first observed by the Chinese in the first century B.C. It is known that at this time Chinese geomancers used a freely turnable spoon-like lodestone on a polished plate as a compass, not for navigational purposes, but probably for aligning tombs and houses. As navigational instrument the compass was introduced to European sailors by arabic merchants in the twelfth century A.C. A first systematic experimental study of the forces exerted by lodestones was published by Petrus Peregrinus in 1269. Some of his results are shown in Figure 1a. More refined experiments...
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Busse, F.H. (2011). Geomagnetic Field, Theory. In: Gupta, H.K. (eds) Encyclopedia of Solid Earth Geophysics. Encyclopedia of Earth Sciences Series. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-8702-7_103
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