超高圧地球科学:最下部マントル・中心核の物質学

2008 Fiscal Year Annual Research Report

• Project/Area Number: 19674003
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: 廣瀬 敬 Tokyo Institute of Technology, 大学院・理工学研究科, 教授 (50270921)
• Keywords: マントル / 核 / ポストペロフスカイト / 超高圧

Research Abstract

本研究は地球の最下部マントルおよび中心核に相当する超高圧高温状態を実験室で実現し、地球深部の物性を実験的に明らかにしようとするものである。本年度は、まずX線回折実験の結果、MgSiO3組成におけるポストペロフスカイト相転移境界を170万気圧4400ケルビンに至る幅広い圧力温度条件下で決定することに成功し、コア・マントル境界圧力における転移温度は約3500ケルビンであることがあきらかになった。地震学的観測で得られている対の不連続面の深さからマントル最下部の温度構造を見積もることに成功した。また適当な熱伝導率を仮定すると、コアからの熱流量は約7テラワット程度であることがわかった。さらに、Fe-Ni系の状態図を300万気圧2000ケルビンまで決定し、Niの存在によりfcc構造相の安定領域が大きく拡大することがあきらかになった。また、超高圧下で合成した試料の化学組成分析を行った結果、最下部マントル鉱物間における鉄分配と鉄の2価・3価比を決定し、ポストペロフスカイト相はぺロフスカイト相よりもやや鉄に乏しいこと、鉄の2価・3価比は両相ともあまり変わらないことがあきらかになった。

Research Products

• [Journal Article] Development of in situ Brillouin spectroscopy at high pressure and high temperature with synchrotron radiation and infrared laser heating system : Application to the Earth's deep interior (2009)
  • Author(s): Murakami, M., Asahara, Y., Ohishi, Y., Hirao, N., Hirose. K
  • Journal Title: Physics of the Earth and Planetary Interiors (in press)
  • Peer Reviewed
• [Journal Article] Elasticity of MgO to 130 GPa : Implications for lower mantle mineralogy (2009)
  • Author(s): Murakami, M., Ohishi, Y. Hirao, N., Hirose, K.
  • Journal Title: Earth and Planetary Science Letters 277 Pages: 123-129
  • Peer Reviewed
• [Journal Article] Determination of post-perovskite phase transition boundary in MgSiO3 up to 4400 K and implications for thermal structure at the base of the mantle (2009)
  • Author(s): Tateno, S., Hirose. K., Sata, N., Ohishi, Y
  • Journal Title: Earth and Planetary Science Letters 277 Pages: 130-136
  • Peer Reviewed
• [Journal Article] Stagnant slab : A review (2009)
  • Author(s): Fukao, Y., et al. the Deep Slab Project Group (Utada, H., et al. Hirose, K.)
  • Journal Title: Annual Review of the Earth and Planetary Science (in press)
  • Peer Reviewed
• [Journal Article] Experimental study of reaction between perovskite and molten iron to 146 GPa and implications for chemical equilibrium at the core-mantle boundary (2009)
  • Author(s): Ozawa, H., Hirose, K., Mitome, M., Bando, Y., Sata, N., Ohishi, Y
  • Journal Title: Physic and Chemistry of Minerals (in press)
  • Peer Reviewed
• [Journal Article] 高圧実験とマントルの相転移 (2009)
  • Author(s): 廣瀬 敬
  • Journal Title: 地震 (印刷中)
  • Peer Reviewed
• [Journal Article] Phase relations of iron-silicon alloys at high pressure and high temperature (2009)
  • Author(s): Kuwayama, Y., Sawai, T., Hirose, K., Sata, N., Ohishi, Y
  • Journal Title: Physics and Chemistry of Minerals (in press)
  • Peer Reviewed
• [Journal Article] Dissociation of CAS phase in the uppermost lower mantle (2008)
  • Author(s): Ishibashi, K., Hirose, K., Sata, N., Ohishi, Y
  • Journal Title: Physics and Chemistry of Minerals 35 Pages: 197-200
  • Peer Reviewed
• [Journal Article] Chemical equilibrium between ferropericlase and molten iron to 134 GPa and implications for iron content at the bottom of the mantle (2008)
  • Author(s): Ozawa, H., Hirose, K., Mitome, M., Bando, Y., Sata, N., Ohishi, Y
  • Journal Title: Geophysical Research Letters 35 Pages: L05308, doi:10.
  • 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 320 Pages: 89-91
  • Peer Reviewed
• [Journal Article] Discovery of post-perovskite phase transition and new views on the core-mantle boundary region (2008)
  • Author(s): Hirose. K., Lay
  • Journal Title: Elements 4 Pages: 183-189
  • Peer Reviewed
• [Journal Article] Simultaneous volume measurements of Au and MgO to 140 GPa and thermal equation of state of Au based on MgO pressure scale (2008)
  • Author(s): Hirose, K., Sata, N., Komabayashi, T., Ohishi, Y
  • Journal Title: Physics of the Earth and Planetary Interiors 167 Pages: 149-154
  • Peer Reviewed
• [Journal Article] PVT relations in MgO : an ultra-high P-T scale for planetary science applications (2008)
  • Author(s): Wu, Z., R. Wentzcovitch, K. Umemoto, Li, B., Hirose, K., Zheng, J
  • Journal Title: Journal of Geophysical Research 113 Pages: doi: 10.1029/2007JB005275
  • Peer Reviewed
• [Journal Article] The compression of H2O ice to 126 GPa and implications for hydrogen-bond symmetrization : Synchrotron x-ray diffraction measurements and density-functional calculations (2008)
  • Author(s): Sugimura, E., Iitaka, T., Hirose, K., Kawamura, K., Sata, N., Ohishi, Y
  • Journal Title: Physical Review B 77 Pages: 214103-214103
  • Peer Reviewed
• [Journal Article] Iron partitioning between perovskite and post-perovskite : A transmission electron microscope study (2008)
  • Author(s): Hirose, K., Takafuii, N., Fujino, K., Shieh, S. R., Duffy, T. S
  • Journal Title: American Mineralogist 93 Pages: 1678-1681
  • Peer Reviewed
• [Journal Article] Ferric iron content in (Mg, Fe)SiO3 perovskite and post-perovskite in the deep lower mantle conditions (2008)
  • Author(s): Sinmyo, R., Ozawa, H. . Hirose. K., Yasuhara, A., Endo, N
  • Journal Title: American Mineralogist 93 Pages: 1899-1902
  • Peer Reviewed
• [Journal Article] Highly intense monochromatic X-ray diffraction facility for high-pressure researchat SPring-8 (2008)
  • Author(s): Ohishi, Y., Hirao, N., Sata, N., Hirose, K., Takata, M
  • Journal Title: High Pressure Research 28 Pages: 163-173
  • Peer Reviewed
• [Journal Article] レーザー加熱式ダイヤモンドセルを用いた(Mg, Fe)SiO3ポストペロフスカイト相の電気伝導度測定 (2008)
  • Author(s): 太田健二, 廣瀬敬, 新名良介, 小野田朱々江, 清水克哉
  • Journal Title: 高圧力の科学と技術 18巻(3) Pages: 260-266
  • Peer Reviewed
• [Journal Article] Partitioning of iron between perovskite/post-perovskite and ferropericlase in the lower mantle (2008)
  • Author(s): Sinmyo, R., Hirose, K., et al.
  • Journal Title: Journal of Geophysical Research 113 Pages: doi: 10.1029/2008JB005730
  • Peer Reviewed
• [Presentation] Experimental study of reaction between perovskite and molten iron to 146 GPa and implications for chemically-distinct buoyant layer at the top of the core (2008)
  • Author(s): Hirose, K
  • Organizer: Fall Meeting, American Geophysical Union
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2008-12-18
• [Presentation] High-pressure phase transitions of deep Earth materials (2008)
  • Author(s): Hirose, K
  • Organizer: IUCr 2008
  • Place of Presentation: Osaka, Japan
  • Year and Date: 2008-08-26