TY - JOUR
T1 - The sound velocity of wüstite at high pressures
T2 - implications for low-velocity anomalies at the base of the lower mantle
AU - Tanaka, Ryosuke
AU - Sakamaki, Tatsuya
AU - Otani, Eiji
AU - Fukui, Hiroshi
AU - Kamada, Seiji
AU - Suzuki, Akio
AU - Tsutsui, Satoshi
AU - Uchiyama, Hiroshi
AU - Baron, Alfred Q.R.
N1 - Funding Information:
This work was supported by JSPS Grants-in-Aid for Scientific Research Grant Numbers 16H01112 and 17H04860 to TS and 15H05748 to EO. Acknowledgements
Publisher Copyright:
© 2020, The Author(s).
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - The longitudinal sound velocity (VP) and the density (ρ) of wüstite, FeO, were measured at pressures of up to 112.3 GPa and temperatures of up to 1700 K using both inelastic X-ray scattering and X-ray diffraction combined with a laser-heated diamond-anvil cell. The linear relationship between VP and ρ, Birch’s law, for wüstite can be expressed as VP = 1.55 (1) × ρ [g/cm3] − 2.03 (8) [km/s] at 300 K and VP = 1.61 (1) × ρ [kg/m3] − 2.82 (10) [km/s] at 1700 K. The sound velocity of wüstite is significantly lower than that of bridgmanite and ferropericlase under lower mantle conditions. In other words, the existence of wüstite in the lower mantle can efficiently decrease the seismic velocity. Considering its slow velocity and several mechanisms for the formation of FeO-rich regions at the core–mantle boundary, we confirm earlier suggestions indicating that wüstite enrichment at the bottom of the Earth’s mantle may contribute to the formation of denser ultra-low velocity zones. [Figure not available: see fulltext.].
AB - The longitudinal sound velocity (VP) and the density (ρ) of wüstite, FeO, were measured at pressures of up to 112.3 GPa and temperatures of up to 1700 K using both inelastic X-ray scattering and X-ray diffraction combined with a laser-heated diamond-anvil cell. The linear relationship between VP and ρ, Birch’s law, for wüstite can be expressed as VP = 1.55 (1) × ρ [g/cm3] − 2.03 (8) [km/s] at 300 K and VP = 1.61 (1) × ρ [kg/m3] − 2.82 (10) [km/s] at 1700 K. The sound velocity of wüstite is significantly lower than that of bridgmanite and ferropericlase under lower mantle conditions. In other words, the existence of wüstite in the lower mantle can efficiently decrease the seismic velocity. Considering its slow velocity and several mechanisms for the formation of FeO-rich regions at the core–mantle boundary, we confirm earlier suggestions indicating that wüstite enrichment at the bottom of the Earth’s mantle may contribute to the formation of denser ultra-low velocity zones. [Figure not available: see fulltext.].
KW - FeO
KW - High pressure
KW - Inelastic X-ray scattering
KW - Seismic low-velocity anomaly
KW - Sound velocity
KW - Wüstite
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U2 - 10.1186/s40645-020-00333-3
DO - 10.1186/s40645-020-00333-3
M3 - Article
AN - SCOPUS:85086127651
VL - 7
JO - Progress in Earth and Planetary Science
JF - Progress in Earth and Planetary Science
SN - 2197-4284
IS - 1
M1 - 23
ER -