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DOI	10.1016/j.epsl.2021.117014
	Strong shear softening induced by superionic hydrogen in Earth's inner core
	Wang W.; Li Y.; Brodholt J.P.; Vočadlo L.; Walter M.J.; Wu Z.
发表日期	2021
ISSN	0012821X
卷号	568
英文摘要	Geophysical and geochemical evidence suggests that Earth's core is predominantly made of iron (or iron-nickel alloy) with several percent of light elements. However, Earth's solid inner core transmits shear waves at a much lower velocity than expected from mineralogical models that are consistent with geochemical constraints. Here we investigate the effect of hydrogen on the elastic properties of iron and iron-silicon alloys using ab initio molecular dynamic simulations. We find that these H-bearing alloys maintain a superionic state under inner-core conditions and that their shear moduli exhibit a strong shear softening due to the superionic effect, with a corresponding reduction in VS. Several hcp-iron-silicon-hydrogen compositions can explain the observed density, VP, VS, and Poisson's ratio of the inner core simultaneously. Our results indicate that hydrogen is a significant component of the Earth's core, and that it may contain at least four ocean masses of water. This indicates that the Earth may have accreted wet and obtained its water from chondritic and/or nebular materials before or during core formation. © 2021 Elsevier B.V.
关键词	ab initio molecular simulations Earth's core high Poisson's ratio low shear velocity shear softening superionic Fe alloy
英文关键词	Geochemistry; Iron alloys; Molecular dynamics; Nickel alloys; Shear flow; Shear waves; Silicon alloys; Ab initio molecular simulation; Earth inner core; Earths cores; High poisson ratio; Inner core; Iron silicon; Low shear velocity; Shear softening; Superionic; Superionic fe alloy; Poisson ratio; alloy; hydrogen; inner core; iron; mantle source; mantle structure; Poisson ratio; shear modulus
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203329
作者单位	Department of Earth Sciences, University College London, London, WC1E 6BT, United Kingdom; Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, 20015, United States; Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Key Laboratory of Crust–Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Center for Excellence in Comparative Planetology, USTC, Hefei, Anhui 230026, China; Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway; National Geophysical Observatory at Mengcheng, USTC, Hefei, Anhui 230026, China
推荐引用方式 GB/T 7714	Wang W.,Li Y.,Brodholt J.P.,et al. Strong shear softening induced by superionic hydrogen in Earth's inner core[J],2021,568.
APA	Wang W.,Li Y.,Brodholt J.P.,Vočadlo L.,Walter M.J.,&Wu Z..(2021).Strong shear softening induced by superionic hydrogen in Earth's inner core.Earth and Planetary Science Letters,568.
MLA	Wang W.,et al."Strong shear softening induced by superionic hydrogen in Earth's inner core".Earth and Planetary Science Letters 568(2021).