Earth's field magnetometry

In the last decade a vast expansion has been experienced in the use of observations and measurements of the Earth's magnetic field. The type and quality of the observations required by newly developed geomagnetic research interests, in themselves partly stimulated by the possibilities offered by new types of magnetometers, greatly increased the amount of effort which has been applied to further developing the instruments and devising new ones. The demand arose from two main sources. The first was the evolution, with the advent of satellite experimentation, of magnetospheric physics, and the second derived from the eventual acceptance of reversed magnetization in rocks as being due to reversal of the Earth's field itself. This paved the way to the chronological interpretation of alternating positive and negative anomalies, and stimulated vigorous research into ocean floor spreading and crustal movements.