A comparison of upper mantle subcontinental electrical conductivity for North America, Europe, and Asia

Main Article Content

W.H. Campbell
E.R. Schiffmacher


Spherical harmonic analysis coefficients of the external and internal parts of the quiet-day geomagnetic field variations (Sq), separated for the North American, European, Central Asian and East Asian regions, were used to determine conductivity profiles to depths of about 600 km by the Schmucker equivalentsubstitute conductor method. All three regions showed a roughly exponential increase of conductivity with depth. Distinct discontinuities seemed to be evident near 255-300km and near 450-600km. Regional differences in the conductivity profiles were shown by the functional fittings to the data. For depths less than about 275 km, the North American conductivities seemed to be significantly higher than the other regions. For depths greater than about 300 km, the East Asian conductivities were largest.

Google Scholar         ARK:/88439/y028414


Article Details

How to Cite
Campbell, W.H., and E.R. Schiffmacher. 1986. “A Comparison of Upper Mantle Subcontinental Electrical Conductivity for North America, Europe, and Asia”. Journal of Geophysics 59 (1), 56-61. https://journal.geophysicsjournal.com/JofG/article/view/232.
Bookmark and Share


Anderson, D.L., Dziewonski, A.M. (1984) Seismic tomography. Sci. Am., 251:58-66

Banks, R.J. (1969) Geomagnetic variations and the electrical conductivity of the upper mantle. Geophys. J. R. Astron. Soc., 17:457-487

Campbell, W.H., Anderssen, R.S. (1983) Conductivity of the subcontinental upper mantel : An analysis using quiet-day geomagnetic records of North America, J. Geomagn. Geoelectr., 35:367-382

Campbell, W.H., Schiffmacher, E.R. (1985) Quiet ionospheric currents of the Northern Hemisphere derived from geomagnetic field records. J. Geophys. Res., 90:6475-6486

Chapman, S., Bartels, J. (1940) Geomagnetism. Clarendon Press, Oxford

Dziewonski, A.M., Anderson, D.L. (1981) Preliminary reference Earth model. Phys. Earth Planet. Inter., 20, 297-356:1981

Lahiri, B.N., Price, A.T. (1939) Electromagnetic induction in nonuniform conductors and the conductivity of the Earth from terrestrial magnetic variations. Phil. Trans. R. Soc. London, A237:509-540

Pollack, H.N., Chapman, D.S. (1977) The flow of heat from the Earth's interior. Seis. Am. 237:60-76

Schmucker, V. (1970) An introduction to induction anomalies. J. Geomagn. Geoelectr., 22:9-33

Schmucker, V. (1979) Erdmagnetische Variationen und die elektrische Leitfahigkeit in tieferen Schichten der Erde. Sitzungsber. Mitt. Braunschw. Wiss. Ges., 4:45-102

Shankland, T.J., Waff, H.S. (1977) Partial melting and electrical conductivity anomalies in the upper mantle. J. Geophys. Res., 82:5409-5417