Fei Yingwei, Ricolleau Angele, Frank Mark, Mibe Kenji, Shen Guoyin, Prakapenka Vitali
Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, Washington, DC 20015, USA.
Proc Natl Acad Sci U S A. 2007 May 29;104(22):9182-6. doi: 10.1073/pnas.0609013104. Epub 2007 May 2.
Our ability to interpret seismic observations including the seismic discontinuities and the density and velocity profiles in the earth's interior is critically dependent on the accuracy of pressure measurements up to 364 GPa at high temperature. Pressure scales based on the reduced shock-wave equations of state alone may predict pressure variations up to 7% in the megabar pressure range at room temperature and even higher percentage at high temperature, leading to large uncertainties in understanding the nature of the seismic discontinuities and chemical composition of the earth's interior. Here, we report compression data of gold (Au), platinum (Pt), the NaCl-B2 phase, and solid neon (Ne) at 300 K and high temperatures up to megabar pressures. Combined with existing experimental data, the compression data were used to establish internally consistent thermal equations of state of Au, Pt, NaCl-B2, and solid Ne. The internally consistent pressure scales provide a tractable, accurate baseline for comparing high pressure-temperature experimental data with theoretical calculations and the seismic observations, thereby advancing our understanding fundamental high-pressure phenomena and the chemistry and physics of the earth's interior.
我们解释地震观测结果（包括地震间断面以及地球内部的密度和速度剖面）的能力，严重依赖于在高温下高达364吉帕斯卡压力测量的准确性。仅基于简化冲击波状态方程的压力标度，在室温下的兆巴压力范围内可能预测压力变化高达7%，在高温下甚至更高，这导致在理解地震间断面的性质和地球内部化学成分方面存在很大的不确定性。在此，我们报告了金（Au）、铂（Pt）、NaCl-B2相和固态氖（Ne）在300K以及高达兆巴压力的高温下的压缩数据。结合现有的实验数据，这些压缩数据被用于建立Au、Pt、NaCl-B2和固态Ne的内部一致的热状态方程。内部一致的压力标度为将高压-温度实验数据与理论计算以及地震观测结果进行比较提供了一个易于处理、准确的基线，从而推进了我们对基本高压现象以及地球内部化学和物理的理解。
