COMPRESSIONAL WAVE VELOCITY IN OLIVINE NODULES AT HIGH PRESSURE AND TEMPERATURE

Low-temperature olivine rheology at high pressure

San-Carlos olivine rheology was investigated at pressure (P) up to 9 GPa and temperature (T) lower than 890 ◦C. Six powder specimens were cold compressed and sintered into dense and compact materials, then deformed during relaxation experiments carried out at constant pressure and temperature in DIA-type cubic-anvil apparatus. Sample elastic strain was monitored during relaxation by in situ X-r...

Compressional and shear wave velocities of Fe2SiO4 spinel at high pressure and high temperature

The Temperature Sensitivity of Elastic Wave Velocity at High Pressure: New Results for Molybdenum

A new experimental technique is described whereby a material is heated to very high temperature (T), shock compressed to high pressure (P) (and higher T), and the compressional elastic wave velocity of the high P and T state is measured. This method has been applied to the high-pressure standard molybdenum at pressures between 12 and 81 GPa and at an initial temperature of 1400øC. The compressi...

Empirical relation for estimating shear wave velocity from compressional wave velocity of rocks

In situ shear wave velocity is one of the most important parameters for evaluating dynamic elastic moduli and needs special energy sources for generation and receivers for detection. Identification of shear wave phase on a seismic record needs skill as it is not the first wave to arrive and is usually embedded in surface waves. To estimate shear wave velocity for site characterization and for p...

Effect of borehole stress concentration on compressional wave velocity measurements

Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could lead to a biased estimation of formation elastic properties measured from sonic logging data. To study the effect of stress concentration around a borehole on sonic logging, we first use an iterative approach, which combines a rock physics model a...