Elastic properties and equation of state of high pressure ice

Abstract

Measurements of compressional and shear wave velocities at −25 °C at pressures up to about 0.7 GPa show that the elastic properties of the high pressure polymorphs of ice are significantly different from the values for the room pressure phase. Data were obtained from ice Ih, III, V, and VI. The bulk modulus decreases slightly when ice Ih transforms to ice III while the shear modulus increases by nearly 50%. Both moduli increase substantially going from ice III to ice V. The bulk modulus of ice VI at 0.625 GPa is more than 50% greater than ice Ih and the shear modulus is more than two and one half times as large as for ice Ih. Apart from the interest in these properties for a material as important as ice, the results may be used in interpreting the internal structure and orbital histories of the icy satellites of the outer planets.