Seismic attenuation measurement by cyclic loading under high pressure and temperature

An experimental method to study the seismic attenuation factor (Q-1) and anelastic properties of materials at high pressure and high temperature has been established by using the multianvil high-pressure deformation device (D-DIA) and a synchrotron X-ray radiography at SPring8. Time resolved images of the sample and reference material provide their strain as a function of time during cyclic loading. Attenuation is determined as the tangent of the angle of phase lag between the sample and the reference material. A newly installed short period sinusoidal cyclic loading oil pressure system enable us to determine minimal strain of the sample in a wide frequency range from 2 to 0.01 hertz on olivine aggregates at 1 GPa and up to 1673 K. The detectable minimum strain is around 5×10^-5. Several test experiments exhibited resolvable Q^-1 (10^-2) above 1273 K. The results are generally consistent with previously reported data.