2019 Fiscal Year Final Research Report

Dynamic behaviour of core and mantle materials

Planned Research

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Project Area	Interaction and Coevolution of the Core and Mantle: Toward Integrated Deep Earth Science
Project/Area Number	15H05827
Research Category	Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Allocation Type	Single-year Grants
Review Section	Science and Engineering
Research Institution	Okayama University
Principal Investigator	Yoshino Takashi 岡山大学, 惑星物質研究所, 教授 (30423338)
Co-Investigator(Kenkyū-buntansha)	西原遊愛媛大学, 地球深部ダイナミクス研究センター, 准教授 (10397036) 平賀岳彦東京大学, 地震研究所, 准教授 (10444077) 太田健二東京工業大学, 理学院, 准教授 (20727218) 久保友明九州大学, 理学研究院, 教授 (40312540) 安東淳一広島大学, 理学研究科, 教授 (50291480)
Project Period (FY)	2015-06-29 – 2020-03-31
Keywords	核 / マントル / 熱伝導 / 拡散 / クリープ / 高圧実験 / 核ーマントル境界
Outline of Final Research Achievements	From the viewpoint of heat and mass transport processes, we have promoted research on physical property measurement of deep earth materials. From the thermal conductivity measurement, only the temperature inhomogeneity inside the mantle due to mantle convection is the cause of regional difference of heat flow in CMB. Nuclear mantle interactions can produce negative anomalies in the W isotope ratio of oceanic island basalts. From the high-pressure deformation experiment, the lower mantle is about an order of magnitude stronger than the mantle transition layer. The deformation of the subducted slab is mainly due to the diffusion creep due to the phase transition and subsequent grain refinement, except for the marginal part of the retained slab where the selective orientation due to dislocation creep has developed. The anisotropy observed in the D "layer is formed by the selective orientation due to particle rotation, and the viscosity of the plume is higher than that of the slab.
Free Research Field	高圧地球科学
Academic Significance and Societal Importance of the Research Achievements	今まで独立に扱われることの多かった核とマントルの研究をその相互作用と同じ物性をそれぞれ測定することにより、それぞれの動的な挙動の理解を有機的に結びつけ、新たな地球深部ダイナミクスの理解につなげた。多様な実験技術の開発に成功し、今後進むであろう研究の方向性の確立に大きな役割を果たした。