Fig. 10

Geophysical models of electrical conductivity in the oceanic upper mantle from the magnetotelluric observations. a Results away from the mid-ocean ridge (from Sarafian et al. 2015). Mid Pacific (70 Myrs old oceanic region). Electrical conductivity increases smoothly with depth without any peak. b Results near the east Pacific Rise (from Evans et al. 2005). There is a peak in conductivity at the top of the asthenosphere. Some anisotropy is also reported (high along the direction of plate motion, low normal to it both in the horizontal plane)