Composition of the Earth's inner core from high-pressure sound velocity measurements in Fe-Ni-Si alloys

被引：103

作者：

Antonangeli, Daniele ^{[1
,2
]}

Siebert, Julien ^{[1
,2
]}

Badro, James ^{[1
,2
]}

Farber, Daniel L. ^{[2
,3
]}

Fiquet, Guillaume ^{[1
]}

Morard, Guillaume ^{[1
]}

Ryerson, Frederick J. ^{[2
]}

机构：

[1] Univ Paris Diderot, Univ Paris 06, Inst Phys Globe Paris, Inst Mineral & Phys Milieux Condenses,CNRS,UMR 75, F-75005 Paris, France

[2] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[3] Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Santa Cruz, CA 95064 USA

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2010年 / 295卷 / 1-2期

关键词：

Fe-Ni-Si alloy; aggregate compressional and shear sound; velocities; high pressure; inner core; light elements; AB-INITIO CALCULATIONS; LIGHT-ELEMENTS; OUTER CORE; IRON; TEMPERATURE; CONSTRAINTS; SULFUR; ELASTICITY; LIQUID; PHASES;

D O I：

10.1016/j.epsl.2010.04.018

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We performed room-temperature sound velocity and density measurements on a polycrystalline alloy, Fe0.89Ni0.04Si0.07, in the hexagonal close-packed (hcp) phase up to 108 GPa. Over the investigated pressure range the aggregate compressional sound velocity is similar to 9% higher than in pure iron at the same density. The measured aggregate compressional (V-P) and shear (V-S) sound velocities, extrapolated to core densities and corrected for anharmonic temperature effects, are compared with seismic profiles. Our results provide constraints on the silicon abundance in the core, suggesting a model that simultaneously matches the primary seismic observables, density, P-wave and S-wave velocities, for an inner core containing 4 to 5 wt.% of Ni and 1 to 2 wt.% of Si. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：292 / 296

页数：5

共 47 条

[1] Composition and temperature of the Earth's core constrained by combining ab initio calculations and seismic data [J].