R
Ryuichi Nomura
Researcher at Ehime University
Publications - 23
Citations - 813
Ryuichi Nomura is an academic researcher from Ehime University. The author has contributed to research in topics: Mantle (geology) & Transition zone. The author has an hindex of 9, co-authored 21 publications receiving 637 citations. Previous affiliations of Ryuichi Nomura include Tokyo Institute of Technology & Kyoto University.
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Journal ArticleDOI
Low core-mantle boundary temperature inferred from the solidus of pyrolite.
Ryuichi Nomura,Kei Hirose,Kei Hirose,Kentaro Uesugi,Yasuo Ohishi,Akira Tsuchiyama,Akira Miyake,Yuichiro Ueno +7 more
TL;DR: The experimentally determined maximum melting point of 3570 kelvin suggests that some phases typically thought to lose stability in the lowermost mantle, such as MgSiO3-rich post-perovskite, may be more widely distributed than expected.
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Spin crossover and iron-rich silicate melt in the Earth’s deep mantle
Ryuichi Nomura,Ryuichi Nomura,Haruka Ozawa,Haruka Ozawa,Shigehiko Tateno,Kei Hirose,Kei Hirose,John Hernlund,Shunsuke Muto,Hirofumi Ishii,Nozomu Hiraoka +10 more
TL;DR: Nomura et al. as discussed by the authors showed that a spin crossover occurs at about 76 GPa, resulting in stronger iron enrichment in melts at higher pressures, suggesting that the observed change in iron partitioning could be explained by spin crossover of iron (from high spin to low-spin) in silicate melt.
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Magnesium Partitioning Between Earth's Mantle and Core and its Potential to Drive an Early Exsolution Geodynamo
James Badro,James Badro,Julien Aubert,Kei Hirose,Kei Hirose,Ryuichi Nomura,I. Blanchard,Stephan Borensztajn,Julien Siebert,Julien Siebert +9 more
TL;DR: In this paper, the incorporation of magnesium oxide (one of the main components of Earth's mantle) into iron (the main constituent Earth's core), using extremely high pressure and temperature experiments that mimic the conditions of Earth’s mantle and core.
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Reconciling magma‐ocean crystallization models with the present‐day structure of the Earth's mantle
TL;DR: In this paper, the authors use geodynamic models with a moving-boundary approach to study convection and mixing within the growing cumulate layer, and thereafter within the fully crystallized mantle.
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Melt–crystal density crossover in a deep magma ocean
Razvan Caracas,Razvan Caracas,Kei Hirose,Kei Hirose,Ryuichi Nomura,Ryuichi Nomura,Maxim D. Ballmer,Maxim D. Ballmer,Maxim D. Ballmer +8 more
TL;DR: In this article, the first bridgmanite crystal formed in a fully molten mantle is Fe-poor and becomes neutrally buoyant at 110-120 GPa, and at 50% solidification, close to the rheological transition, the pressure of density crossover moves to ∼50 GPa.