Determination of post-perovskite phase transition boundary up to 4400 K and implications for thermal structure in D″ layer
Determination of post-perovskite phase transition boundary up to 4400 K and implications for thermal structure in D″ layer
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DOI：
10.1016/j.epsl.2008.10.004
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发表时间：
2009-01
影响因子：
5.3
通讯作者：
Shigehiko Tateno;K. Hirose;N. Sata;Y. Ohishi
中科院分区：
文献类型：
--
作者：
Shigehiko Tateno;K. Hirose;N. Sata;Y. Ohishi
我们已经确定了后钙钛矿相转变边界的MgSiO 3在一个宽的温度范围从1640至4380 K在119-171 GPa的基础上同步辐射X射线衍射测量原位在高压和高温下在激光加热的金刚石砧室（LHDAC）。结果表明，在核幔边界压力下，克拉珀龙斜率为+13.3 ~1.0 MPa/K，转变温度为3520±70 K。D″层的热结构可以由精确确定的后钙钛矿相变边界和成对地震不连续面的深度来严格约束。这表明CMB的温度可能在3700 K左右，比以前认为的要低一些。来自核心的全球热流的最小界限估计为6.6±0.5 TW。
We have determined the post-perovskite phase transition boundary in MgSiO3in a wide temperature range from 1640 to 4380 K at 119–171 GPa on the basis of synchrotron X-ray diffraction measurements in-situ at high-pressure and -temperature in a laser-heated diamond-anvil cell (LHDAC). The results show a considerably high positive Clapeyron slope of +13.3±1.0 MPa/K and a transition temperature of about 3520±70 K at the core–mantle boundary (CMB) pressure. The thermal structure in D″ layer can be tightly constrained from precisely determined post-perovskite phase transition boundary and the depths of paired seismic discontinuities. These suggest that temperature at the CMB may be around 3700 K, somewhat lower than previously thought. A minimum bound on the global heat flow from the core is estimated to be 6.6±0.5 TW.