Ono Shigeaki
Volcanoes and Earth's Interior Research Center, Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan.
Sci Rep. 2020 Feb 3;10(1):1393. doi: 10.1038/s41598-020-58252-8.
The physical properties of argon (Ar) are investigated to 382 GPa and 3000 K using diamond anvil cell experiments and first-principles molecular dynamics. The estimated density of Ar is smaller that of the Preliminary reference Earth model (PREM) mantle, which indicates that the density crossover does not occur at the bottom of the lower mantle. A large volume dependence of the thermal pressure of Ar is revealed at pressures higher than 200 GPa, and a significant temperature dependence of the calculated effective Grüneisen parameters is confirmed at high pressures. A melting temperature of Ar is estimated from the calculation data and a significant pressure dependence is confirmed. If the pressure-temperature path of the subducted slab is lower than the critical condition, ~750 K and ~7.5 GPa, solid Ar can be carried down into the deep mantle. Melting of solid Ar in the upwelling mantle plume occurs at the bottom of the transition zone. Thus, solid Ar plays an important role in Ar recycling in the Earth's interior.
利用金刚石对顶砧实验和第一性原理分子动力学方法，对氩（Ar）在382吉帕斯卡压力和3000开尔文温度下的物理性质进行了研究。估计的氩密度小于初步参考地球模型（PREM）下地幔的密度，这表明在下地幔底部不会发生密度交叉。在高于200吉帕斯卡的压力下，揭示了氩热压力对体积的强烈依赖性，并且在高压下证实了计算出的有效格林艾森参数对温度的显著依赖性。根据计算数据估算了氩的熔化温度，并证实了其对压力的显著依赖性。如果俯冲板块的压力-温度路径低于临界条件，即约750开尔文和约7.5吉帕斯卡，固态氩就可以被携带到下地幔深处。固态氩在上涌的地幔柱中会在过渡带底部发生熔化。因此，固态氩在地球内部的氩循环中起着重要作用。
