Temperature Coefficient of Sound Velocity of Perovskite-Enstatite and Lateral Thermal Heterogeneity in Earth's Lower Mantle

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2000,（3）
• 所属期刊栏目: Condensed matter:structure,mechanical and thermal
• 页码范围: 218-220
• 页数: 3页
• 语种: 英文

摘要

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, 0.255m/(s.K) at 40GPa to 0.197, 0.131, 0. 162m/(s.K) at 140GPa, respectively. Extrapolating these to zero pressure results in ( K/ T)0 =-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.