Composition of the Earth's inner core from high-pressure sound velocity measurements in Fe–Ni–Si alloys - Archive ouverte HAL
Article Dans Une Revue Earth and Planetary Science Letters Année : 2010

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

Résumé

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 not, vert, similar 9% higher than in pure iron at the same density. The measured aggregate compressional (VP) and shear (VS) 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.

Dates et versions

hal-00536210 , version 1 (15-11-2010)

Identifiants

Citer

Daniele Antonangeli, Julien Siebert, James Badro, Daniel L. Farber, Guillaume Fiquet, et al.. Composition of the Earth's inner core from high-pressure sound velocity measurements in Fe–Ni–Si alloys. Earth and Planetary Science Letters, 2010, 295 (1-2), pp.292-296. ⟨10.1016/j.epsl.2010.04.018⟩. ⟨hal-00536210⟩
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