THE ELECTRICAL-CONDUCTIVITY OF H2O AT 0.21-4.18 GPA AND 20-350-DEGREES-C

The electrical conductivity of H2O in solid and liquid phases has been measured at 0.21-4.18 GPa and 20-355 degrees C. The results indicate: (i) different phases of H2O in solid have different relations between electrical conductivity and temperature and pressure. The conductivit y changes continuously with temperature, but discontinuously with the pressure between 2.11 and 2.58 GPa, which corresponds to the transform ing pressure between ice (VI) and ice (VII); (ii) the conductivity of H2O in liquid all increases with temperature and pressure, but there a re discontinuities at pressures between 0.57 and 0.9 GPa, and between 2.11 and 2.58 GPa, which are also consistent with the polymorph of ice (ice (V), ice (VI) and ice (VII)). This reflects that H2O in liquid a t different pressures has quite different properties of electron chemi stry. It is probably the important reason that causes the layers with high electrical conductivity and low velocity in the earth's crust and upper mantle.