The electrical conductivity of H2O at 0.21– 4.18 GPa and 20–350°C

The electrical conductivity of H₂O in solid and liquid phases has been measured at 0.21–4.18 GPa and 20–350°C. The results indicate: (I) different phases of H₂O in solid have different relations between electrical conductivity and temperature and pressure. The conductivity changes continuously with temperature, but discontinuously with the pressure between 2.11 and 2.58 GPa, which corresponds to the transforming pressure between ice (VI) and ice (VII);(II) the amductivity of H₂O in liquid all increases with temperature and pressure, but there are discontinuities at pressures between 0.57 and 0.9 GPa, and between 2.11 and 2.58 GPa, which are also consistent with the polyrnorph of ice (ice (V), ice (VI) and ice (VII)). This reflects that H₂O in liquid at different pressures has quite different properties of electron chemistry. It is probably the important reason that causes the layers with high electrical conductivity and low velocity in the earth’s ceust and upper mantle.