Mantle, Electrical Conductivity, Mineralogy
The electrical conductivity profile in the mantle can be obtained by magnetotelluric ( q.v.) and geomagnetic deep sounding ( q.v.) methods (Figure M181). Although the profiles obtained can have significant differences from each other, the following features can be seen in the most conductivity models. Conductivity in the upper mantle is relatively low, i.e., 10 −4–10 −2 S m −1. It increases with increasing depth to the top of the lower mantle. At the top of the lower mantle, conductivity is 10 0 S m −1. Conductivity does not increase significantly in the lower mantle. Some studies have shown that the electrical conductivity of the uppermost mantle to 100 km depth is about 10 −2∼10 −1 S m −1, known as the mantle high conductive layer (HCL). Local variations of electrical conductivity are large at shallow depths, and become smaller with increasing depth.
- Poirier, J.‐P., 2000. Introduction to the physics of the Earth's interior, 2nd edn. Cambridge: Cambridge University Press.Google Scholar
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