Electrical and thermal conduction properties of Earth's core

• Project/Area Number: 26707029
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Kenji Ohta 東京工業大学, 理学院, 講師 (20727218)
• Research Collaborator: HIROSE Kei ; OHISHI Yasuo ; SUEHIRO Sho
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥23,920,000 (Direct Cost: ¥18,400,000、Indirect Cost: ¥5,520,000); Fiscal Year 2016: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2015: ¥12,350,000 (Direct Cost: ¥9,500,000、Indirect Cost: ¥2,850,000); Fiscal Year 2014: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
• Keywords: 地球中心核 / 鉄合金 / 電気伝導度 / 熱伝導率 / 高温高圧実験 / 純鉄の電気抵抗率 / 硫黄の不純物抵抗 / 岩石・鉱物・鉱床学 / 高圧実験

Outline of Final Research Achievements

Electrical and thermal conductivities are fundamental physical properties to know thermal structure and evolution of Earth's interior. However, there is few report regarding the conductivity measurements under the Earth's core conditions. The purpose of this study is to measure the electrical conductivity of iron-light element alloys that may consist of the Earth's core under very high pressures and temperatures, and to reveal electrical and thermal conductivity profile of the Earth. After some technical developments, we succeeded to measure the electrical conductivity of iron at the core conditions. In addition, we revealed the effect of sulfur and hydrogen incorporation on the conductivity of iron at high pressure and temperature conditions. The findings in this study will be a fundamental information to consider thermal structure and evolution of Earth and other terrestrial planets.

Research Products

• [Int'l Joint Research] Sorbonne university(France)
• [Journal Article] Thermal conductivity of ferropericlase in the Earth’s lower mantle (2017)
  • Author(s): K. Ohta, T. Yagi, K. Hirose, Y. Ohishi
  • Journal Title: Earth and Planetary Science Letters Volume: 465 Pages: 29-37
  • DOI: 10.1016/j.epsl.2017.02.030
  • Peer Reviewed
• [Journal Article] Experimental determination of the electrical resistivity of iron at Earth’s core conditions (2016)
  • Author(s): Kenji Ohta, Yasuhiro Kuwayama, Kei Hirose, Katsuya Shimizu, Yasuo Ohishi
  • Journal Title: Nature Volume: 印刷中 Issue: 7605 Pages: 95-98
  • DOI: 10.1038/nature17957
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Compression of Fe-Si-H alloys to core pressures (2016)
  • Author(s): Shoh Tarawa, Kenji Ohta, Kei Hirose, Chie Kato, Yasuo Ohishi
  • Journal Title: Geophysical Research Letters Volume: 印刷中
  • NAID: 120006582503
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Phase boundary of hot dense fluid hydrogen (2015)
  • Author(s): Kenji Ohta, Kota Ichimaru, Mari Einaga, Sho Kawaguchi, Katsuya Shimizu, Takahiro Matsuoka, Naohisa Hirao, Yasuo Ohishi
  • Journal Title: Scientific Reports Volume: 5 Issue: 1 Pages: 16560-16560
  • DOI: 10.1038/srep16560
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Heating of Li in hydrogen : possible synthesis of LiHx (2015)
  • Author(s): K. Kuno, T. Matsuoka, T. Nakagawa, N. Hirao, Y. Ohishi, K. Shimizu, K. Takahama, K. Ohta, M. Sakata, T. Kume, S. Sasaki
  • Journal Title: High Pressure Research Volume: 35 Issue: 1 Pages: 16-21
  • DOI: 10.1080/08957959.2014.999677
  • Peer Reviewed
• [Journal Article] Measurements of lattice thermal conductivity of MgO to core-mantle boundary pressures (2014)
  • Author(s): Saori Imada, Kenji Ohta, Takashi Yagi, Kei Hirose, Hideto Yoshida, Hiroko Nagahara
  • Journal Title: Geophysical Research Letters Volume: 41 Issue: 13 Pages: 4542-4547
  • DOI: 10.1002/2014gl060423
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Highly conductive iron-rich (Mg,Fe)O magnesiowustite and its stability in the Earth's lower mantle (2014)
  • Author(s): Ohta, K., Fujino, K., Kuwayama, Y., Kondo, T., Shimizu, K., Ohishi, Y
  • Journal Title: Journal of Geophysical Research : Solid Earth Volume: 119-6 Issue: 6 Pages: 4656-4665
  • DOI: 10.1002/2014jb010972
  • Peer Reviewed
• [Journal Article] Pressure-induced reentrant metallic phase in lithium (2014)
  • Author(s): T. Matsuoka, M. Sakata, Y. Nakamoto, K. Takahama, K. Ichimaru, K. Mukai, K. Ohta, N. Hirao, Y. Ohishi, K. Shimizu
  • Journal Title: Physical Review B Volume: 89 Issue: 14 Pages: 144103-144103
  • DOI: 10.1103/physrevb.89.144103
  • Peer Reviewed
• [Presentation] Experimental determination of the electrical and thermal conductivity of iron at Earth’s core conditions (2016)
  • Author(s): Kenji Ohta, Yasuhiro Kuwayama, Kei Hirose, Katsuya Shimizu, Yasuo Ohishi, Takashi Yagi, Sho Suehiro
  • Organizer: American Geophysical Union, 2016 Fall meeting
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2016-12-12
  • Int'l Joint Research / Invited
• [Presentation] Thermal conductivity of iron at high pressures (2016)
  • Author(s): Sho Suehiro, Kenji Ohta, Takashi Yagi, Kei Hirose
  • Organizer: American Geophysical Union, 2016 Fall meeting
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2016-12-12
  • Int'l Joint Research
• [Presentation] Thermal conductivity of iron at high pressures and temperature (2016)
  • Author(s): Sho Suehiro, Kenji Ohta, Takashi Yagi, Kei Hirose
  • Organizer: The 57th High Pressure Conference of Japan
  • Place of Presentation: Tsukuba, Japan
  • Year and Date: 2016-10-26
• [Presentation] Compression behavior of Fe-Si-H alloys (2015)
  • Author(s): Tagawa, S., Ohta, K., Hirose, K., Ohishi, Y.
  • Organizer: American Geophysical Union, 2015 Fall meeting
  • Place of Presentation: Coscone center, San Fransisco, CA USA
  • Year and Date: 2015-12-14
  • Int'l Joint Research
• [Presentation] Measurement of electrical conductivity of liquid Fe-S alloy at high pressures and temperatures (2015)
  • Author(s): Suehiro, S., Ohta, K., Hirose, K., Morard, G., & Ohishi Y.
  • Organizer: 第56回日本高圧力学会高圧討論会
  • Place of Presentation: 広島県広島市
  • Year and Date: 2015-11-10
• [Presentation] Measurements of electrical and thermal conductivity of deep Earth materials under multimegabar pressures (2015)
  • Author(s): Ohta, K., Yagi, T., Hirose, K., Shimizu, K., Kuwayama, Y., Ohishi, Y.
  • Organizer: 第56回日本高圧力学会高圧討論会
  • Place of Presentation: 広島県広島市
  • Year and Date: 2015-11-10
• [Presentation] Development of thermal diffusivity measurement apparatus using diamond anvil cell to explore extreme high pressure and high temperature conditions (2015)
  • Author(s): Yagi, T., & Ohta, K.
  • Organizer: 36th Japan Symposium on thermophysical properties,
  • Place of Presentation: 東北大学
  • Year and Date: 2015-11-01
• [Presentation] Experimental constraints on the electrical and thermal conductivity of the Earth’s core-mantle boundary (2015)
  • Author(s): Ohta, K.
  • Organizer: Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS), 2015 Annual Meeting
  • Place of Presentation: 東京大学
  • Year and Date: 2015-10-31
  • Invited
• [Presentation] The effect of sulfur on the electrical resistivity of iron and implications for planetary cores (2015)
  • Author(s): Suehiro, S., Ohta, K., Hirose, K., & Ohishi Y.
  • Organizer: 25th V.M. Goldschmidt conference
  • Place of Presentation: Prague Congress Center, Prague, Czech Republic
  • Year and Date: 2015-08-16
  • Int'l Joint Research
• [Presentation] Fcc FeHx at core pressure (2015)
  • Author(s): Kato, C., Ohta, K., Hirose, K., Ohishi, Y.
  • Organizer: 25th V.M. Goldschmidt conference
  • Place of Presentation: Prague Congress Center, Prague, Czech Republic
  • Year and Date: 2015-08-16
  • Int'l Joint Research
• [Presentation] The electrical resistivity of iron alloys at Earth’s core conditions (2015)
  • Author(s): Ohta, K., Suehiro, S., Hirose, K., & Ohishi Y.
  • Organizer: 25th V.M. Goldschmidt conference
  • Place of Presentation: Prague Congress Center, Prague, Czech Republic
  • Year and Date: 2015-08-16
  • Int'l Joint Research
• [Presentation] Measurements of electrical and thermal conductivity of iron under Earth’s core conditions (2014)
  • Author(s): Ohta, K., Kuwayama, Y., Shimizu, K., Yagi, T., Hirose, K., Ohishi, Y.
  • Organizer: American Geophysical Union, 2014 Fall meeting
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2014-12-15 – 2014-12-19
  • Invited
• [Presentation] Electrical resistivity of iron under Earth’s core conditions (2014)
  • Author(s): Ohta, K., Kuwayama, Y., Hirose, K., Shimizu, K., Ohishi, Y.
  • Organizer: 第55回高圧討論会
  • Place of Presentation: 徳島大学
  • Year and Date: 2014-11-22 – 2014-11-24
• [Presentation] Experimental constraints on thermal conductivity of the core-mantle boundary region (2014)
  • Author(s): Ohta, K.
  • Organizer: The 14th symposium of SEDI (Study of Deep Earth Interior)
  • Place of Presentation: The Shonan Village Center, Kanagawa, Japan
  • Year and Date: 2014-08-03 – 2014-08-08
  • Invited
• [Presentation] Electrical resistivity of iron in the Earth’s core conditions (2014)
  • Author(s): Ohta, K., Kuwayama, Y., Hirose, K., Shimizu, Ohishi, Y.
  • Organizer: Gordon Research Conference on High Pressure, Research at
  • Place of Presentation: University of New England, Biddeford, ME, USA
  • Year and Date: 2014-06-22 – 2014-06-27
• [Presentation] Electrical resistivity of hcp-Fe under core conditions (2014)
  • Author(s): Ohta, K., Kuwayama, Y., Hirose, K., Ohishi, Y.
  • Organizer: Japan Geoscience Union Meeting 2014
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-04-28 – 2014-05-02
• [Remarks] Kenji Ohta's homepage
  • URL: http://kenjiohta-uhpr.sakura.ne.jp/Kenji_Ohtas_homepage/Welcome.html
• [Remarks] 研究代表者の個人ホームページ
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• [Remarks] 研究代表者の研究室のホームページ
  • URL: http://www.geo.titech.ac.jp/lab/ohta/Ohta_Lab._HP/Ohta_Lab_Home.html
• [Remarks] 太田健二 個人ホームページ
  • URL: http://kenjiohta-uhpr.sakura.ne.jp/Kenji_Ohtas_homepage/Welcome.html
• [Remarks] 東京工業大学 大学院理工学研究科 地球惑星科学専攻 太田研究室ホームページ
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