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Thermal interaction of the core and the mantle and long-term behavior of the geomagnetic fieldThe effects of temperature changes at the earth's core-mantle boundary on the velocity field of the core are analyzed. It is assumed that the geomagnetic field is maintained by thermal convection in the outer core. A model for the thermal interaction of the core and the mantle is presented which is consistent with current views on the presence of heat sources in the core and the properties of the lower mantle. Significant long-term variations in the frequency of geomagnetic reversals may be the result of fluctuating temperatures at the core-mantle boundary, caused by intermittent convection in the lower mantle. The thermal structure of the lower mantle region D double prime, extending from 2700 to 2900 km in depth, constitutes an important test of this hypothesis and offers a means of deciding whether the geomagnetic dynamo is thermally driven.
Document ID
19770048052
Document Type
Reprint (Version printed in journal)
Authors
Jones, G. M. (California, University Berkeley, Calif., United States)
Date Acquired
August 8, 2013
Publication Date
April 10, 1977
Publication Information
Publication: Journal of Geophysical Research
Volume: 82
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NGR-09-015-002
CONTRACT_GRANT: NSF DES-74-19365
CONTRACT_GRANT: NSF GA-1682
Distribution Limits
Public
Copyright
Other