The observed strength of the Earth's magnetic field is due to two sources: the main geomagnetic field of the Earth that originates deep within the Earth and the magnetic field anomalies caused by magnetized parts of the Earth's crust. For any point on the Earth, the main field strength can be calculated and removed from the observed value to give the magnetic field strength anomaly. These and other methods of removing the trend from magnetic surveys have been discussed by Bullard (1967).
Contours of magnetic anomaly strength show a configuration or pattern at sea that is fundamentally different from that found on land. Data taken off the west coast of North America first revealed the linear pattern of anomalies over the oceanic crust (Fig. 1). Other major lineation patterns were subsequently reported for the east coast of North America, for the Reykjanes Ridge off southwestern Iceland (Fig. 2), for large parts of the Pacific Ocean (Fig. 3), for large parts of the South Atlantic Ocean,...
This is a preview of subscription content, log in via an institution to check access.
References
Blakely, R. J., and Cande, S. C., 1979, Marine magnetic anomalies, Rev. Geophys. 17, 204–214.
Blakely, R. J.; Klitgord, K. D.; and Mudie, J. D., 1975, Analysis of marine magnetic data, Rev. Geophys. 13, 182–185.
Bullard, E. C., 1967, The removal of trend from magnetic surveys, Earth and Planetary Sci. Letters 2, 293–300.
Harrison, C. G. A., 1983, Magnetic anomalies, Rev. Geophys. 21, 634–643.
Heirtzler, J. R., 1970, Measurements of magnetic anomalies at sea, in A. Maxwell, ed., The Sea, vol. 4. New York: John Wiley & Sons.
Heirtzler, J. R., 1981, Marine magnetic anomaly studies during the 1970's, in Paleoreconstruction of the Continents, McElhinng and Valencio, eds. Washington, D.C.: Amer. Geophys. Unions, pp. 50–54.
Heirtzler, J. R.; Dickson, G. O.; Herron, E. M.; Pitmann, W. C., III; and Le Pichon, X., 1968, Marine magnetic anomalies, geomagnetic field reversals and motions of the ocean floor and continents, Jour. Geophys. Research 73, 2119–2136.
Heirtzler, J. R., and Vogt, P. R., 1971, Marine magnetic anomalies and their bearing on polar wandering and continental drift, EOS 52, 220–224.
Herron, E. M., and Pitman, W. C., 1975, Marine magnetic anomalies as related to plate tectonics, Rev. Geophys. 13, 180–182.
Johnson, H. P., 1979, Magnetization of the oceanic crust, Rev. Geophys. 17, 215–226.
Larson, R. L., 1975, Marine magnetics, Rev. Geophys. 13, 529–531.
Larson, R. L., 1976, Late Jurassic and Early Cretaceous evolution of the western central Pacific Ocean, Jour. Geomagnetism and Geoelectricity 28, 219–236.
Larson, R., and Helsley, C. E., 1975, Mesozoic reversal sequence, Rev. Geophys. 13, 174–176.
Vine, F. J., and Matthews, D. H., 1963, Magnetic anomalies over oceanic ridges, Nature 199, 747–749.
Rights and permissions
Copyright information
© 1987 Van Nostrand Reinhold Company Inc.
About this entry
Cite this entry
Heirtzler, J.R. (1987). Oceanic crust, geomagnetic patterns . In: Structural Geology and Tectonics. Encyclopedia of Earth Science. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-31080-0_73
Download citation
DOI: https://doi.org/10.1007/3-540-31080-0_73
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-0-442-28125-0
Online ISBN: 978-3-540-31080-8
eBook Packages: Springer Book Archive