Melting curve of water studied in externally heated diamond-anvil cell

The melting curve of ice VII was measured to a maximum pressure of 38 GPa (temperature of about 1000 K). Experiments were carried out in an externally heated diamond anvil cell and melting was monitored by the disappearance of X-ray diffraction from ice VII. The melting line of H2O was found to be well described by the Simon equation P = 2.2 + 1.31 [(T/365)(3.3) - 1].