DOI: 10.1016/j.epsl.2019.116009
论文题名: Chemical compositions of the outer core examined by first principles calculations
作者: Umemoto K. ; Hirose K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 531 语种: 英语
中文关键词: chemical composition
; first principles
; liquid under high pressure
; outer core
英文关键词: Acoustic wave velocity
; Chemical elements
; Geochemistry
; Iron alloys
; Liquids
; Molecular dynamics
; Chemical compositions
; First principles
; First principles molecular dynamics
; First-principles calculation
; High pressure
; Inner core boundary
; outer core
; Pressure and temperature
; Calculations
; accretion
; alloy
; bulk density
; chemical composition
; geochemistry
; hydrogen
; outer core
; P-T conditions
英文摘要: We have examined the density and bulk sound velocity of liquid iron alloys, (Fe, Ni)X(H, Si, O, S, C)1-X, at Earth's outer core pressure and temperature conditions based on first-principles molecular dynamics simulations. The nonideal mixing effects on volume and velocity were found to be negligible for all combinations of different liquid alloys examined. By comparing the results with seismological observations, we searched for possible chemical compositions for the outer core. Hydrogen is found to be a primary light element when the inner-core boundary temperature TICB is 4,800 K to 5,400 K. If this is the case, it is suggested that a large amount of water was delivered to the Earth during its accretionary stage and that the present-day core temperature is relatively low. On the other hand, oxygen is the most important light element if TICB = 6,000 K, consistent with the previous calculations by Badro et al. (2014) at TICB = 6,300 K. To further constrain the chemical composition of the outer core, it is necessary to take into account other constraints besides its density and bulk sound velocity; melting temperature, simultaneous solubilities of multiple of light elements, and so forth. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165319
Appears in Collections: 气候变化与战略
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作者单位: Earth-Life Science Institute, Tokyo Institute of Technology, Meguro, Tokyo, 150-8550, Japan; Department of Earth and Planetary Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
Recommended Citation:
Umemoto K.,Hirose K.. Chemical compositions of the outer core examined by first principles calculations[J]. Earth and Planetary Science Letters,2020-01-01,531