Recent Studies on Ultrasonic Measurements under High Pressure and a New Analytical Methodology for Ultrasonic Velocity Data at Simultaneous High Pressure and High Temperature

Basic techniques for ultrasonic measurements are discussed with emphasis placed on accuracy of sound velocity. Recent ultrasonic studies under high pressure are briefly reviewed, and a new analytical methodology called the complete thermodynamic equation of state is introduced. The potential of the method is demonstrated by analyzing a synthetic model data set. The results suggest that the method can be used to constrain thermodynamic parameters, such as heat capacity and thermal expansivity, up to pressures of the core-mantle boundary using experimental data collected only up to 10 Gpa.