| Project/Area Number |
19H02002
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 17040:Solid earth sciences-related
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| Research Institution | Ehime University |
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Principal Investigator |
Greaux Steeve 愛媛大学, 地球深部ダイナミクス研究センター, 講師 (90543166)
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| Co-Investigator(Kenkyū-buntansha) |
肥後 祐司 公益財団法人高輝度光科学研究センター, 回折・散乱推進室, 主幹研究員 (10423435)
河合 研志 東京大学, 大学院理学系研究科(理学部), 准教授 (20432007)
佐藤 友彦 岡山理科大学, 基盤教育センター, 准教授 (80714831)
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000)
Fiscal Year 2022: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2021: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2020: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2019: ¥9,880,000 (Direct Cost: ¥7,600,000、Indirect Cost: ¥2,280,000)
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| Keywords | mantle composition / high pressure / ultrasonic measurement / seismological model / triplication |
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| Outline of Research at the Start |
P- and S-wave velocities are the unique tool we have to explore the inaccessible deep Earth. To this day however, comparison of laboratory data with global seismological models has given no unique answer due to the complexity of the mantle as suggested by the growing evidences for compositional heterogeneities widespread across the globe. Here we propose a new approach, which consist in elucidating locally regions of stagnating slabs, independently from global models, on the basis of laboratory sound velocity measurements, geological record of the slab and local seismological observations.
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| Outline of Final Research Achievements |
In this research project, we conducted an investigation into the seismicity of regions with stagnating slabs, independently of global models. Our investigation was based on laboratory sound velocity measurements, geological records of the slab, and local seismological observations. Through the application of advanced ultrasonic interferometry and synchrotron X-ray techniques, we were able to perform experiments at the pressures and temperatures of the upper mantle (up to 2300 K at pressures of ~3-10 GPa), mantle transition zone (up to 2100 K at pressures of ~12-22 GPa), and uppermost lower mantle (up to 2100 K at pressures of ~24-27 GPa). These techniques were applied to investigate the sound velocities of pyrolite, Mid-Ocean Ridge Basalt (MORB), and harzburgite rock aggregates, as well as other relevant minerals and rock compositions. The results of our investigation have broad implications for the fields of Earth and planetary sciences.
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| Academic Significance and Societal Importance of the Research Achievements |
The velocity models derived from our datasets enable us to constrain the local structure and composition of the mantle and subducted slabs, extending up to the uppermost lower mantle. This has implications for our understanding of Earth's internal dynamics and evolution throughout geological time.
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