Ultrahigh-Pressure Earth Science : Study of Lowermost mantle and core materials

2011 Fiscal Year Final Research Report

• Project/Area Number: 19674003
• Research Category: Grant-in-Aid for Young Scientists (S)
• Allocation Type: Single-year Grants
• Research Field: Solid earth and planetary physics
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: HIROSE Kei 東京工業大学, 大学院・理工学研究科, 教授 (50270921)
• Project Period (FY): 2007 – 2011
• Keywords: マントル / 核 / ポストペロフスカイト / 超高圧

Research Abstract

We first succeeded in generating static ultrahigh-pressure and-temperature conditions. We also developed new experimental methods to determine electrical and thermal conductivity and element partitioning at high pressure and temperature. With such techniques, we determined properties of the deep lower mantle and the phase relations in Fe and FeO at core pressures and temperatures. These results clarified the density crossover between melt and solid in the deep mantle, the cause of change in length of a day in decadal timescales, possible stratification in the outer core, and the crystal structure of inner core material.

Research Products

• [Journal Article] A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity data (2012)
  • Author(s): Murakami, M., Ohishi, Y., Hirao, N., Hirose, K.
  • Journal Title: Nature
  • DOI: doi:10.1038/nature11004
  • Peer Reviewed
• [Journal Article] Spin crossover and iron-rich silicate melt in the Earth's deep mantle (2011)
  • Author(s): Nomura, R., Ozawa, H., Tateno, S., Hirose, K., Hernlund, J., Muto, S., Ishii, H., Hiraoka, N.
  • Journal Title: Nature Volume: 473 Pages: 199-202
  • Peer Reviewed
• [Journal Article] Phase transition in FeO and stratification in Earth's outer core (2011)
  • Author(s): Ozawa, H., Takahashi, F., Hirose, K., Ohishi, Y., Hirao, N.
  • Journal Title: Science Volume: 334 Pages: 792-794
  • Peer Reviewed
• [Journal Article] Compression of FeSi, Fe3C, Fe0. 950, and FeS under the core pressures and implication for light element in the Earth's core (2010)
  • Author(s): Sata, N., Hirose, K., Shen, G., Ohishi, Y., Hirao, N.
  • Journal Title: Journal of Geophysical Research Volume: 115, 2 Pages: B09204
  • DOI: doi:10.1029/2009JB006975
  • Peer Reviewed
• [Journal Article] The structure of iron in Earth's inner core (2010)
  • Author(s): Tateno, S., Hirose, K., Ohishi, Y., Tatsumi, Y.
  • Journal Title: Science Volume: 330 Pages: 359-361
  • Peer Reviewed
• [Journal Article] Determination of post-perovskite phase transition boundary in MgSiO3 up to 4400K and implications for thermal structure at the base of the mantle (2009)
  • Author(s): ateno, S., Hirose, K., Sata, N., Ohishi, Y.
  • Journal Title: Earth and Planetary Science Letters Volume: 277 Pages: 130-136
  • Peer Reviewed
• [Journal Article] The electrical conductivity of post-perovskite in Earth's D' layer (2008)
  • Author(s): Ohta, K., Onoda, S., Hirose, K., Sinmyo, R., Shimizu, K., Sata, N., Ohishi, Y., Yasuhara, A.
  • Journal Title: Science Volume: 320 Pages: 89-91
  • Peer Reviewed
• [Journal Article] Phase relations of iron and iron-nickel alloys up to 300 GPa ; Implications for the composition and the structure of the Earth's inner core (2008)
  • Author(s): Kuwayama, Y., Hirose, K., Sata, N., Ohishi, Y.
  • Journal Title: Earth and Planetary Science Letters Volume: 273 Pages: 379-385
  • Peer Reviewed
• [Presentation] Discovery of post-perovskite and its geophysical implications(Keynote talk) (2011)
  • Author(s): Hirose, K.
  • Organizer: International Union of Crystallography
  • Place of Presentation: マドリード
  • Year and Date: 2011-08-24
• [Presentation] Perovskite and Post-perovskite in the Earth's Deep Mantle (2010)
  • Author(s): Hirose, K.
  • Organizer: International Mineralogical Assembly
  • Place of Presentation: ブダペスト
  • Year and Date: 2010-08-27
• [Presentation] High-pressure studies of core materials (2009)
  • Author(s): Hirose, K.
  • Organizer: Gordon Conference
  • Place of Presentation: ボストン
  • Year and Date: 2009-06-18
• [Presentation] Partitioning of iron in the lower mantle (2007)
  • Author(s): Hirose, K.
  • Organizer: American Geophysical Union
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2007-12-12
• [Presentation] Discovery of post-perovskite and the new views of core-mantle boundary region (2007)
  • Author(s): Hirose, K.
  • Organizer: International Union of Geodesy and Geophysics 2007
  • Place of Presentation: ペルージャ
  • Year and Date: 2007-07-06
• [Remarks]
  • URL: http://www.geo.titech.ac.jp/lab/hirose/research.html