Using the differences of sound velocity and temperature on the Hugoniot and isoentropic state,the temperature coefficients of sound velocity of perovskite-enstatite under high pressure were obtained.For compressional,...Using the differences of sound velocity and temperature on the Hugoniot and isoentropic state,the temperature coefficients of sound velocity of perovskite-enstatite under high pressure were obtained.For compressional,shear and bulk wave velocities,their temperature coefficients decrease from 0.386,0.251,0.255 m/(s·K)at 40 GPa to 0.197,0.131,0.162m/(S·K)at 140GPa,respectively.Extrapolating these to zero pressure results in(■K/■T)o=-0.0279 GPa·K^(-1),which is consistent very well with the value got by hydrostatic pressure experiment.On the basis of our data,we conclude that the compressional wave velocity anomaly of 0.1-0.2%in the deep lower mantle and 2%in the D″region would imply lateral thermal heterogeneity with amplitude of 53-106 K and 1066 K in these regions,respectively.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.19672058the Science and Technology Foundation of Chinese Academy of Engineering Physics under Grant No.960103.
文摘Using the differences of sound velocity and temperature on the Hugoniot and isoentropic state,the temperature coefficients of sound velocity of perovskite-enstatite under high pressure were obtained.For compressional,shear and bulk wave velocities,their temperature coefficients decrease from 0.386,0.251,0.255 m/(s·K)at 40 GPa to 0.197,0.131,0.162m/(S·K)at 140GPa,respectively.Extrapolating these to zero pressure results in(■K/■T)o=-0.0279 GPa·K^(-1),which is consistent very well with the value got by hydrostatic pressure experiment.On the basis of our data,we conclude that the compressional wave velocity anomaly of 0.1-0.2%in the deep lower mantle and 2%in the D″region would imply lateral thermal heterogeneity with amplitude of 53-106 K and 1066 K in these regions,respectively.
