Study of origin of seismic ultra-low velocity zone at bottom of lower mantle

2008 Fiscal Year Final Research Report

• Project/Area Number: 18684030
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: ONO Shigeaki Japan Agency for Marine-Earth Science and Technology, 地球内部変動研究センター, 主任研究員 (20313116)
• Project Period (FY): 2006 – 2008
• Keywords: 地震波低速度層 / コア / マントル / 高温高圧

Research Abstract

地震学的手法によって存在が示唆されている下部マントル最下部での地震波の低速度層に注目して、その起源を明らかにすることを目的とした。鉄化合物を合成して、高温高圧その場測定を行い、それぞれの物性を決定した。その結果、固体の物性変化のみでは説明することが困難であり、低速度層の起源として、液体の存在が必要であることが導かれた。さらに、ケイ酸塩メルトより、鉄のメルトの方が観測結果をうまく説明できることがわかった。

Research Products

• [Journal Article] Phase transitions of BaCO3 at high pressures (2008)
  • Author(s): S. Ono, J. P. Brodholt, G. D. Price
  • Journal Title: Mineralogical Mag. 72 Pages: 659-665
  • Peer Reviewed
• [Journal Article] Ab initio molecular dynamics simulations for thermal equation of state of B2-type NaCl (2008)
  • Author(s): S. Ono, J. P. Brodholt, D. Alfe, M. Alfredsson, G. D. Price
  • Journal Title: J. Appl. Phys. 103 Pages: 023510
  • Peer Reviewed
• [Journal Article] Structural phase transitions in IrO2 at high pressures (2008)
  • Author(s): S. Ono, J. P. Brodholt, G. D. Price
  • Journal Title: J. Phys. Condens. Matter 20 Pages: 045202
  • Peer Reviewed
• [Journal Article] First-principles simulation of high-pressure polymorphs in MgAl_2O_4 (2008)
  • Author(s): S. Ono, J. P. Brodholt, G. D. Price
  • Journal Title: Phys. Chem. Minerals 35 Pages: 381-386
  • Peer Reviewed
• [Journal Article] High-pressure phase transformations of FeS : novel phases at conditions of planetary cores (2008)
  • Author(s): S. Ono, A. R. Oganov, J. P. Brodholt, L. Vocadlo, I. G. Wood, A. Lyakhov, C. W. Glass, A. S. Cote, G. D. Price
  • Journal Title: Earth Planet. Sci. Lett. 272 Pages: 481-487
  • Peer Reviewed
• [Journal Article] Experimental constraints on the temperature profile in the lower mantle (2008)
  • Author(s): S. Ono
  • Journal Title: Phys. Earth Planet. Inter. 170 Pages: 267-273
  • Peer Reviewed
• [Journal Article] High-Pressure Transition of CaCO_3 (2007)
  • Author(s): S. Ono
  • Journal Title: Am. Mineral. 92 Pages: 1246-1249
  • Peer Reviewed
• [Journal Article] The Lehmann discontinuity due to dehydration of subducted sediment (2007)
  • Author(s): S. Ono
  • Journal Title: The Open Mineralogy Journal 1 Pages: 1-4
  • Peer Reviewed
• [Journal Article] Static compression of high-pressure phase FeSi (2007)
  • Author(s): S. Ono
  • Journal Title: Eur. J. Mineral 19 Pages: 183-187
  • Peer Reviewed
• [Journal Article] High-pressure study of rhombohedral iron oxide, FeO, at pressures between 41 and 142 GPa (2007)
  • Author(s): S. Ono, Y. Ohishi, T. Kikegawa
  • Journal Title: J. Phys. Condens. Matter 19 Pages: 036205
  • Peer Reviewed
• [Journal Article] Stability and compressibility of the high-pressure phases of Al_2O_3 up to 200 GPa : implications for the electrical conductivity of the base of the lower mantle (2006)
  • Author(s): S. Ono, A. R. Oganov, T. Koyama, H. Shimizu
  • Journal Title: Earth Planet. Sci. Lett. 246 Pages: 326-335
  • Peer Reviewed
• [Journal Article] Structural properties of CaIrO_3-type MgSiO_3 up to 144 GPa (2006)
  • Author(s): S. Ono, T. Kikegawa, Y. Ohishi
  • Journal Title: Am. Mineral. 91 Pages: 475-478
  • Peer Reviewed
• [Journal Article] Structural property of CsCl-type sodium chloride under pressure (2006)
  • Author(s): S. Ono, T. Kikegawa, Y. Ohishi
  • Journal Title: Solid State Commun. 137 Pages: 517-522
  • Peer Reviewed
• [Journal Article] High-pressure study of FeS, between 20 and 120 GPa, using synchrotron X-ray powder diffraction (2006)
  • Author(s): S. Ono, T. Kikegawa
  • Journal Title: Am. Mineral. 91 Pages: 1941-1944
  • Peer Reviewed
• [Presentation] Synergy Between High-pressure Experiment and First-principle Computation in Study of Earth's Deep Interior (2008)
  • Author(s): Shigeaki Ono
  • Organizer: AGU Fall Meeting
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2008-12-18
• [Presentation] 高圧条件での鉄および鉄化合物の磁気相転移 (2008)
  • Author(s): 小野重明
  • Organizer: 日本鉱物科学会年会
  • Place of Presentation: 秋田
  • Year and Date: 2008-09-20
• [Presentation] Pressure-induced phase transition of iron sulfide and iron carbide (2008)
  • Author(s): Shigeaki Ono
  • Organizer: EMPG2008
  • Place of Presentation: インスブルック
  • Year and Date: 2008-09-08
• [Presentation] Magnetic transition and equation of state of iron carbide to 400 GPa (2008)
  • Author(s): Shigeaki Ono
  • Organizer: IUCr 2008
  • Place of Presentation: 大阪
  • Year and Date: 2008-08-26
• [Presentation] 地球内部条件での炭酸塩鉱物の安定性 (2008)
  • Author(s): 小野重明
  • Organizer: 連合大会
  • Place of Presentation: 幕張
  • Year and Date: 2008-05-25
• [Presentation] Lehmann discontinuity due to dehydration of phengite (2007)
  • Author(s): Shigeaki Ono
  • Organizer: AGU Fall Meeting 2007
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2007-12-14
• [Presentation] High-pressure syntheses of new carbonate phases (2007)
  • Author(s): S. Ono
  • Organizer: IUCr Workshop, Advances in High Pressure Crystallography at Large Scale Facilities
  • Place of Presentation: オックスフォード
  • Year and Date: 2007-09-04
• [Presentation] Magnetic phase transition of FeS at high pressures (2007)
  • Author(s): Shigeaki Ono
  • Organizer: 24^<nd> European Crystallographic Meeting
  • Place of Presentation: モロッコ
  • Year and Date: 2007-08-25
• [Presentation] Phase boundary of decomposition of kyanite at high P-T (2007)
  • Author(s): S. Ono
  • Organizer: Frontiers in Mineral Sciences 2007
  • Place of Presentation: ケンブリッジ
  • Year and Date: 2007-06-26
• [Presentation] Phase transition of CaCO_3 up to 200 GPa and 2600 K (2007)
  • Author(s): Shigeaki Ono
  • Organizer: EGU Meeting
  • Place of Presentation: ウィーン
  • Year and Date: 2007-04-17
• [Presentation] High-pressure studies of FeO, FeSi, and FeS (2006)
  • Author(s): Shigeaki Ono
  • Organizer: AGU Fall Meeting 2006
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2006-12-15
• [Presentation] Physics and chemistry of CaIrO_3-type postperovskite phase (2006)
  • Author(s): Shigeaki Ono
  • Organizer: 16^<th> Annual V. M. Goldschmidt Conference
  • Place of Presentation: メルボルン
  • Year and Date: 2006-08-28