地球中心核の構成と進化

2009 Fiscal Year Annual Research Report

• Project/Area Number: 18104009
• Research Institution: Tohoku University
• Principal Investigator: 大谷 栄治 Tohoku University, 大学院・理学研究科, 教授 (60136306)
• Co-Investigator(Kenkyū-buntansha): 鈴木 昭夫 東北大学, 大学院・理学研究科, 准教授 (20281975) ; 寺崎 英紀 東北大学, 大学院・理学研究科, 助教 (50374898)
• Keywords: 地殻・マントル物質 / 固体地球物理学 / 岩鉱・鉱物・鉱床学 / 地球惑星内部構造 / 高温・高圧

Research Abstract

本研究では、内核を構成する物質の解明、内核の成長にともなう地球核の分化作用の解明、外核を構成する金属液体の物性の解明、外核とマントルの反応様式の解明を目標にしている。
具体的には、平成21年度は以下のような成果を上げることができた。
金属鉄合金の高圧相の探索と内核の構成の研究
1.より高温を安定に発生するためにダイヤモンドアンビルの試料部構成や加熱システムの改良を行った。特に圧媒体をMgO,Al2O3,アルゴンなど各種を試みた。
2.FeSi系合金およびFeS系合金などの高温高圧安定相、融点を核の圧力で決定する。FeSi合金、FeNiSi合金の高温高圧相関係を250GPa,3500K以上の条件で決定した。これらの条件でhcp構造相が安定であることが明らかになった。また、Fe3S相が220GPa,3500K程度まで安定であることを明らかにした。
3.FeNi合金、FeNiSi合金等の状態方程式を300GPa以上の条件で決定し、金属鉄合金の密度に対するNi,Si等の影響を評価した。これらの効果は、小さくこれを評価するには圧力精度の向上が不可欠であることが明らかになった。
金属鉄とケイ酸塩および含水鉱物との反応の解明:
4.金属鉄と金属鉄軽元素液体の間のPt,Os,Reの元素分配を100GPaの条件まで明らかにした。Os同位体異常の原因が地球核内部で生じる内核分別作用が原因ではないことが明らかになった。
5.金属鉄ニッケル合金と含水鉱物(含水δAlOOHや含水リングウッダイト)との高温高圧下での反応を解明した。高温高圧下で、含水鉱物は分解し、水素は金属鉄に吸収されることを示した。
金属鉄軽元素系の液体物性と核物質の変形流動の解明:
6.これまでのFe-S系液体の組成と密度関係に加えて、高温高圧下でのFe-Si系の液体の密度を浮沈法によって明らかにした。その結果、Fe-Si系においてもFe-S系と同様、非理想性を示し、負の混合の体積を示すことが明らかになった。

Research Products

• [Journal Article] Phase relationship of the Fe-FeS system in conditions up to the Earth's outer core (2010)
  • Author(s): Kamada S., Terasaki H., Ohtani E., Sakai T., Kikegawa T., Ohishi Y., Hirao N., Sata N., Kondo T.
  • Journal Title: Earth and Planetary Science Letters (未定, 印刷中) Pages: 1
• [Journal Article] Density measurement of Fe3C liquid using X-ray absorption image up to 10GPa and effect of light elements on compressibility of liquid iron (2010)
  • Author(s): Terasaki H., Nishida K., Shibazaki Y., Sakamaki T., Suzuki A., Ohtani E., Kikegawa T.
  • Journal Title: Journal of Geophysical Research (未定, 印刷中) Pages: 1
• [Journal Article] The partitioning of Pt-Re-Os between solid and liquid metal in the Fe-Ni-S system at high pressure : Implications for inner core fractionation (2009)
  • Author(s): H.Hayashi, E Ohtani, H.Terasaki, Y.Ito
  • Journal Title: Geochimica et Cosmochimica Acta 73 Pages: 4836-4842
  • Peer Reviewed
• [Journal Article] Advances in high-pressure mineral physics : From the deep mantle to the core (2009)
  • Author(s): E Ohtani, D.Andrault, P.D. Asimow, L.Stixrude, Y.Wang
  • Journal Title: Physics of the Earth and Planetary Interiors 174 Pages: 1-2
  • Peer Reviewed
• [Journal Article] Melting relations and the equation of state of magmas at high pressure : application to geodynamics (2009)
  • Author(s): E Ohtani
  • Journal Title: Chemical Geology 265 Pages: 279-288
  • Peer Reviewed
• [Journal Article] Eutectic temperatures and melting relations in the Fe-O-S system at high pressures and temperatures (2009)
  • Author(s): Tsuno K., Ohtani E.
  • Journal Title: Physics and Chemistry of Minerals 36 Pages: 9-17
  • Peer Reviewed
• [Journal Article] In situ measurement of interfacial tension of Fe-S and Fe-P liquids under high pressure using X-ray radiography and tomography techniques (2009)
  • Author(s): H.Terasaki, S.Urakawa, K.Funakoshi, N.Nishiyama, Y.Wang, K.Nishida, T.Sakamaki, A.Suzuki, E Ohtani
  • Journal Title: Physics of the Earth and Planetary Interiors 174 Pages: 220-226
  • Peer Reviewed
• [Journal Article] Fe-Mg partitioning between perovskite and ferropericlase in the lower mantle (2009)
  • Author(s): T.Sakai, E Ohtani, H.Terasaki, N.Sawada, Y.Kobayashi, M.Miyahara, M.Nishijima, N.Hirao, Y.Ohishi, T.Kikegawa
  • Journal Title: American Mineralogist 94 Pages: 921-925
  • Peer Reviewed
• [Journal Article] Hydrogen partitioning between Iron and Ringwoodite : Implications for water transport into the Martian core (2009)
  • Author(s): Y.Shibazaki, E Ohtani, H.Terasaki, A.Suzuki, K.Funakoshi
  • Journal Title: Earth Planet.Science Lett 287 Pages: 463-470
  • Peer Reviewed
• [Journal Article] Measurement of diffusion process of iron atoms under high pressure of hydrogen by time-domain analysis of nuclear resonant scattering of X-rays (2009)
  • Author(s): Kasai H., Kawauchi T., Fukai Y., Zhang XW., Kishimoto S., Kikegawa T., Ohtani E., Okano T.
  • Journal Title: Applied Surface Science 256 Pages: 984-986
  • Peer Reviewed
• [Presentation] X線イメージング法により融体の研究とその地球・惑星内部への適用 (2010)
  • Author(s): 大谷栄治, 鈴木昭夫, 寺崎英紀, 白石令, 西田圭佑, 柴崎裕樹, 立山隆二, 久保友明, 加藤工, 下宿彰, 土井菜保子, 西原遊
  • Organizer: 第27回PFシンポジウム
  • Place of Presentation: つくば
  • Year and Date: 20100309-20100310
• [Presentation] X線吸収画像を用いた高温高圧下におけるFeS融体及びFe3C融体の密度測定 (2010)
  • Author(s): 西田圭佑, 寺崎英紀, 大谷栄治, 鈴木昭夫, 柴崎裕樹, 立山隆二, 亀卦川卓美
  • Organizer: 第27回PFシンポジウム
  • Place of Presentation: つくば
  • Year and Date: 20100309-20100310
• [Presentation] 浮沈法を用いた高圧下におけるFe-Si液体合金の密度測定 (2010)
  • Author(s): 立山隆二, 大谷栄治, 寺崎英紀, 西田圭佑, 鈴木昭夫, 柴崎裕樹, 亀卦川卓美
  • Organizer: 第27回PFシンポジウム
  • Place of Presentation: つくば
  • Year and Date: 20100309-20100310
• [Presentation] Deformation Cubic Anvil Pressと単色X線を用いたファヤライトの変形実験 (2010)
  • Author(s): 白石令, 大谷栄治, 鈴木昭夫, 久保友明, 土井菜保子, 下宿彰, 加藤工, 亀卦川卓美
  • Organizer: 第27回PFシンポジウム
  • Place of Presentation: つくば
  • Year and Date: 20100309-20100310
• [Presentation] Compression study of S-bearing Fe-Ni alloy and(Fe, Ni)3S up to the core pressure conditions (2010)
  • Author(s): Sakai T., Ohtani E., Terasaki H., Kamada S., Hirao N., Sata N.. Ohishi Y.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Melting relationship of Fe-FeS system based on X-ray diffraction. Global-Network symposium on Earth's Dynamics (2010)
  • Author(s): Kamada S., Ohtani E., Terasaki H., Sakai T., Kikegawa T., Ohishi Y., Hirao N., Sata N.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Equation of state of liquid FeS at high pressure and high temperature (2010)
  • Author(s): Nishida K., Ohtani E., Suzuki A, Urakawa S., Sakamaki T., Shibazaki Y., Katayama Y., Kikegawa T.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Iron-Silicate reaction and silicon as a light element in the core (2010)
  • Author(s): 大谷栄治
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Phase relation of Mercury's interior. (2010)
  • Author(s): Ishii M., Ohtani E., Terasaki H., Litasov K.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Phase relation in the C-rich Mg-Fe-Si-O-C system under reducing and oxidizing conditions (2010)
  • Author(s): Takahashi S., Ohtani E., Terasaki H.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Deformation experiment on fayalite using deformation-Cubic Anvil (2010)
  • Author(s): Shiraishi-Ohnuma R., Ohtani E., Suzuki A., Kubo T., Doi N., Shimojuku A., Kato T., Kanagawa K., Kikegawa T
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Melting relation of FeS-H system up to 16.5GPa : Implications for the Ganymede's core. (2010)
  • Author(s): Shibazaki Y., Ohtani E., Terasaki H., Tateyama R., Sakamaki T., Funakoshi K.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Density measurement of liquid Fe-Si using sink-float method under high pressure (2010)
  • Author(s): Tateyama R., Ohtani E., Terasaki H., Suzuki A., Nishida K. Shibazaki Y., Kikegawa T.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] Brillouin scattering and X-ray diffraction of NaCl : a construction of primary pressure scale (2010)
  • Author(s): Takata N., Murakami M., Ohtani E.
  • Organizer: Global-Network symposium on Earth's Dynamics
  • Place of Presentation: Sendai
  • Year and Date: 20100302-20100304
• [Presentation] 浮沈法を用いた高圧下におけるFe-Si液体合金の密度測定 (2010)
  • Author(s): 立山隆二, 大谷栄治, 寺崎英紀, 西田圭佑, 鈴木昭夫, 柴崎裕樹, 亀卦川卓美
  • Organizer: 第3回東北学大学院理学研究科6専攻合同シンポジウム「ヤングブレインズの連携による学際的研究の創造」
  • Place of Presentation: 仙台
  • Year and Date: 2010-02-16
• [Presentation] Distribution of hydrogen in the deep Earth and its role in Earth's dynamics(invited) (2009)
  • Author(s): Ohtani E., Shibazaki Y., Terasaki H.
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] Density measurement of core forming Fe Si liquids at high pressure (2009)
  • Author(s): Ryuji T., Ohtani E., Terasaki H., Nishida K., Suzuki A., Kikegawa T.
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] Deformation experiment on fayalite using deformation-cubic anvil, D-CAP 700, with synchrotron X rays (2009)
  • Author(s): Ohnuma S. R., Ohtani E., Suzuki A., Kubo T., Doi N., Shimojuku A., Kato T., Kikegawa T.
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] ransformation experiment on sodium feldspar using deformation-cubic anvil, D-CAP 700, with synchrotron X rays (2009)
  • Author(s): Doi N., Kato T., Kubo T., Ohnuma S. R., Shimojuku A., Suzuki A, Ohtani E., Kikegawa T.
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] Phase stability of S-bearing Fe-Ni alloy and(Fe, Ni)3S at the core pressure conditions (2009)
  • Author(s): Sakai T., Terasaki H., Ohtani E., Kamada S., Hirao N., Sata N., Ohishi Y
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] Effect of temperature on interfacial tension of liquid Fe-alloy : Possible driving force of metal/silicate separation. Global-Network symposium on Earth's Dynamics (2009)
  • Author(s): Terasaki H., Labrosse S., Urakawa S., Ohtani E.
  • Organizer: 2009 AGU Fall Meeting
  • Place of Presentation: San Francisco(米国)
  • Year and Date: 20091214-20091218
• [Presentation] Stability of Fe3S under the core conditions (2009)
  • Author(s): Kamada S., Terasaki H., Sakai T., Ohtani E., Miyahara M., Asanuma H., Hayashi H., Kikegawa T., Ohishi Y., Hirao N., Sata N.
  • Organizer: Joint AIRAPT-22 & HPCJ-50
  • Place of Presentation: Tokyo
  • Year and Date: 20090726-20090731
• [Presentation] The Si content of the inner core based on the phase relations and compression (2009)
  • Author(s): Asanuma H., Ohtani E., Sakai T., Terasaki H., Hirao N., Sata N., Ohishi Y.
  • Organizer: Joint AIRAPT-22 & HPCJ-50
  • Place of Presentation: Tokyo
  • Year and Date: 20090726-20090731
• [Presentation] High pressure deformation experiments using deformation-Cubic Anvil, D-CAP 700, with synchrotron X rays (2009)
  • Author(s): R.O. Shiraishi., Ohtani E., Kato T., Suzuki A., Shimojuku A., Doi N., Funakoshi K., Higo Y.
  • Organizer: Joint AIRAPT-22 & HPCJ-50
  • Place of Presentation: Tokyo
  • Year and Date: 20090726-20090731
• [Presentation] Density measurement of Fe-C liquid using X-ray absorption image under high pressure (2009)
  • Author(s): Terasaki H., Nishida K., Suzuki A., Ohtani E., Shibazaki Y., Sakamaki T., Kikegawa T.
  • Organizer: Joint AIRAPT-22 & HPCJ-50
  • Place of Presentation: Tokyo
  • Year and Date: 20090726-20090731
• [Presentation] Phase stability of(Fe, Ni)3 at ultra high pressure conditions (2009)
  • Author(s): Sakai T., Kamada S., Terasaki H., Ohtani E., Hirao N., Asanuma H., Sata N., Ohishi Y.
  • Organizer: Joint AIRAPT-22 & HPCJ-50
  • Place of Presentation: Tokyo
  • Year and Date: 20090726-20090731
• [Presentation] Hydrogen incorporation to the Earth's core (2009)
  • Author(s): Terasaki H., Ohtani E., Sakai T., Kamada S., Shibazaki Y., Asanuma H., Naohisa H., Ohishi Y., Sata N., Sakamaki T., Suzuki A., Funakoshi K.
  • Organizer: Goldschmidt 2009
  • Place of Presentation: Davos(スイス)
  • Year and Date: 20090621-20090626
• [Presentation] Density measurement of core forming Fe-Si liquids at high pressure (2009)
  • Author(s): Tateyama R., Ohtani E., Terasaki H., Nishida K., Suzuki A., Kikegawa T.
  • Organizer: 日本地球感星科学連合2009年大会
  • Place of Presentation: 千葉
  • Year and Date: 20090516-20090522
• [Presentation] Pt-Re-Os partitioning between solid and liquid metal in the Fe-Ni-S system (2009)
  • Author(s): Hayashi H., Ohtani E., Terasaki H., Sakai T., Ito Y.
  • Organizer: 日本地球惑星科学連合2009年大会
  • Place of Presentation: 千葉
  • Year and Date: 20090516-20090522
• [Presentation] Effect of hydrogen on the FeS phase diagram with in situ X-ray observation. (2009)
  • Author(s): Shibazaki Y., Ohtani E., Terasaki H., Sakamaki T., Tateyama R., Nishitani N., Funakoshi K., Higo Y.
  • Organizer: 日本地球惑星科学連合2009年大会
  • Place of Presentation: 千葉
  • Year and Date: 20090516-20090522
• [Presentation] Density measurement of liquid FeS using X-ray absorption image up to 10GPa. (2009)
  • Author(s): Nishida K., Ohtani E., Suzuki A., Terasaki H., Shibazaki Y., Sakamaki T., Kikegawa T.
  • Organizer: 日本地球惑星科学連合2009年大会
  • Place of Presentation: 千葉
  • Year and Date: 20090516-20090522
• [Remarks]
  • URL: http://www.ganko.tohoku.ac.jp/bussei/newHP/busseiHP/S_HP14-18/index.html