Magnetization of the earth's crust

A model of the magnetization of the earth's crust, based on measurements of the magnetic field made by NASA satellites Magsat, OGO-2, OGO-4, and OGO-6. This model was also designed to be consistent with other information on the magnetic properties of the earth's crust, such as the contrast in magnetic properties between oceanic and continental crust. Information on the thickness and temperature of the igneous crust is also included in this model. Warm colors (reds) indicate the strongest magnetizations while cool colors (blues) the weakest. Further information can be obtained by contacting Michael Purucker (purucker@geomag.gsfc.nasa.gov).

(click images for larger view)

Global magnetization map

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Bangui anomaly

The cause of the Bangui anomaly (the red or high magnetization region situated over the Central African Republic) is controversial. In 1992 Girdler, Taylor and Frawley (Tectonophysics, vol. 212, p.45-58) proposed that this anomaly was produced by a large meteorite impact at least 1 billion years old. Others have suggested it results from a major fracturing of the crust or the implacement of a large igneous body.

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This page maintained by Jim Roark (SSAI)
Last modified on April 23, 1997