The role of hydrogen in the electrical conductivity of the upper mantle

Abstract

Because of the uncertainties in the hydrogen content of the upper mantle, the conductivity was calculated for several values of this quantity. [...]as the oxygen fugacity in the upper mantle is not well constrained, I have not considered its effect in detail. [...]the experimental data on hydrogen diffusivity were obtained at temperatures of 800-1,000 °C, and extrapolation to higher temperatures was made assuming the same activation energy. The results in Fig. 1 were measured along the axis of highest conductivity. Because the hydrogen diffusivity is anisotropic7, the actual conductivity of olivine aggregates will be somewhat lower because of the spread in orientations.