Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 7 July 1967:
Vol. 157. no. 3784, pp. 55 - 56
DOI: 10.1126/science.157.3784.55
Prev | Table of Contents | Next

Articles

Motions of the Earth's Core and Mantle, and Variations of the Main Geomagnetic Field

Raymond Hide 1

1 Department of Geology and Geophysics and Department of Physics, Massachusetts Institute of Technology, Cambridge 02139

Theoretical work on the magnetohydrodynamics of the earth's liquid core indicates (a) that horizontal variations in the properties of the core-mantle interface that would escape detection by modern seismological methods might nevertheless produce measurable geomagnetic effects; (b) that the rate of drift, relative to the earth's surface, of nonaxisymmetric features of the main geomagnetic field might be much faster than the average zonal speed of hydrodynamic motion of core material relative to the surrounding mantle; and (c) why magnetic astronomical bodies usually rotate. Among the consequences of (a) and (b) are the possibilities that (i) the shortest interval of time that can be resolved in paleomagnetic studies of the geocentric axial dipole component of the earth's magnetic field might be very much longer than the value often assumed by many paleomagnetic workers, (ii) reversals in sign of the geomagnetic dipole might be expected to show some degree of correlation with processes due to motions in the mantle (for example, tectonic activity, polar wandering), and (iii) variations in the length of the day that have hitherto been tentatively attributed to core motions may be due to some other cause.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Equatorially Dominated Magnetic Field Change at the Surface of Earth's Core.
C. C. Finlay and A. Jackson (2003)
Science 300, 2084-2086
   Abstract »    Full Text »    PDF »
Earth's Core and the Geodynamo.
B. A. Buffett (2000)
Science 288, 2007-2012
   Abstract »    Full Text »
Pacific Geomagnetic Secular Variation.
R. R. Doell, R. R. Doell, and A. Cox (1971)
Science 171, 248-254
   Abstract »    PDF »
Geomagnetic Reversals.
A. Cox and A. Cox (1969)
Science 163, 237-245
   PDF »
Precession of the Earth as the Cause of Geomagnetism: Experiments lend support to the proposal that precessional torques drive the earth's dynamo.
W. V. R. Malkus and W. V. R. Malkus (1968)
Science 160, 259-264
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)