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Waveform inversion for the P wave velocity structure in the outermost core

Research Project

Project/Area Number 18K03797
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 17040:Solid earth sciences-related
Research InstitutionThe University of Tokyo

Principal Investigator

Kawai Kenji  東京大学, 大学院理学系研究科(理学部), 准教授 (20432007)

Project Period (FY) 2018-04-01 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Keywords波形インバージョン / 核・マントル境界 / 最外核 / 液体 / マントル / 外核 / 広帯域地震波形 / 固体液体境界 / 異方性 / アレイ観測網 / 震源パラメータ / 震源再決定 / 短周期 / 地震波形インバージョン / マントル最下部 / 軽元素
Outline of Final Research Achievements

To infer the P-wave velocity structure of the outermost core, we developed software for calculating partial derivative in terms of perturbations of density and elastic constants in a liquid media and software for redetermining source parameters to utilize P-waves with short periods. We invert waveform records with shorter periods (up to 8 seconds) for the 3-D S-wave velocity structure of the mantle transition zone and the lowermost mantle, where the phases used to infer the outermost core sample. Thus, these developments will contribute to simultaneous inversion for the seismic velocity structure of the lowermost mantle and the uppermost outer core.

Academic Significance and Societal Importance of the Research Achievements

これまでよりも短い周期のS波を活用することによって、マントル遷移層および最下部マントルの地域的な3次元S波速度構造の最高解像度でのイメージングに成功した。その結果、マントル遷移層の沈み込みスラブの断裂を特定し、地質学的記録と対比することによって世界に先駆けて地球深部の年代決定を行った。また、既存の走時解析手法にとって不得手とされていた地球深部の低速度異常についても、低速度異常の内部構造のイメージングに成功した。本研究ではマントル遷移層および最下部マントルをこれまでにない解像度で地震波速度構造を推定することによって、地球内部ダイナミクスの理解に貢献をすることができた。

Report

(4 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (35 results)

All 2021 2020 2019 2018 2017 Other

All Int'l Joint Research (4 results) Journal Article (10 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 9 results,  Open Access: 5 results) Presentation (21 results) (of which Int'l Joint Research: 9 results,  Invited: 3 results)

  • [Int'l Joint Research] マヒドン大学(タイ)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Academia Sinica(台湾)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] マヒドン大学(タイ)

    • Related Report
      2019 Research-status Report
  • [Int'l Joint Research] Academia Sinica (台湾)(その他の国・地域)

    • Related Report
      2019 Research-status Report
  • [Journal Article] Seismic velocity structure of the upper inner core in the north polar region2021

    • Author(s)
      Ohtaki Toshiki、Tanaka Satoru、Kaneshima Satoshi、Siripunvaraporn Weerachai、Boonchaisuk Songkhun、Noisagool Sutthipong、Kawai Kenji、Kim Taewoon、Suzuki Yuki、Ishihara Yasushi、Miyakawa Koji、Takeuchi Nozomu
    • Journal Title

      Physics of the Earth and Planetary Interiors

      Volume: 311 Pages: 106636-106636

    • DOI

      10.1016/j.pepi.2020.106636

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Effect of normal stress on the frictional behavior of brucite: application to slow earthquakes at the subduction plate interface in the mantle wedge2021

    • Author(s)
      Okuda Hanaya、Katayama Ikuo、Sakuma Hiroshi、Kawai Kenji
    • Journal Title

      Solid Earth

      Volume: 12 Issue: 1 Pages: 171-186

    • DOI

      10.5194/se-12-171-2021

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] High-resolution 3-D S-velocity structure in the D″ region at the western margin of the Pacific LLSVP: Evidence for small-scale plumes and paleoslabs2020

    • Author(s)
      Suzuki, Y., K. Kawai, R. J. Geller, S. Tanaka, W. Siripunvaraporn, S. Boonchaisuk, S. Noisagool, Y. Ishihara, T. Kim,
    • Journal Title

      Physics of the Earth and Planetary Interiors

      Volume: 307 Pages: 106544-106544

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] 3-D S-velocity structure of the mantle transition zone beneath Central America and the Gulf of Mexico inferred using waveform inversion2019

    • Author(s)
      Anselme F. E. Borgeaud, Kenji Kawai, Robert J. Geller
    • Journal Title

      Journal of Geophysical Research: Solid Earth

      Volume: 124 Issue: 9 Pages: 9664-9681

    • DOI

      10.1029/2018jb016924

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] First‐principles Investigation of Frictional Characteristics of Brucite: An Application to Its Macroscopic Frictional Characteristics, Journal of Geophysical Research2019

    • Author(s)
      Hanaya Okuda , Kenji Kawai, Hiroshi Sakuma
    • Journal Title

      Journal of Geophysical Research: Solid Earth

      Volume: 124 Issue: 10 Pages: 10423-10443

    • DOI

      10.1029/2019jb017740

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Thai Seismic Array (TSAR) Project2019

    • Author(s)
      Satoru Tanaka, Weerachai Siripunvaraporn, Songkhun Boonchaisuku, Noisagool Sutthipong, Taweoon Kim, Kenji Kawai, Yuki Suzuki, Yasushi Ishihara, Ryohei Iritani, Koji Miyakawa, Nozomu Takeuchi, Hitoshi Kawakatsu
    • Journal Title

      Bulletin of the Earthquake Research Institute

      Volume: 94 Pages: 1-11

    • NAID

      120006902519

    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Journal Article] The Goshogake mud volcano field, Tohoku, northern Japan: An acidic, high-temperature system related to magmatic volcanism2019

    • Author(s)
      Komatsu, G., R. Ishimaru, N. Miyake, K. Kawai, M. Kobayashi, H. Sakuma, and T. Matsui
    • Journal Title

      Geomorphology

      Volume: 329 Pages: 32-45

    • DOI

      10.1016/j.geomorph.2018.12.035

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Effects of redetermination of source time functions on the 3-D velocity structure inferred by waveform inversion2018

    • Author(s)
      Yamaya, L., A.F.E. Borgeaud, K. Kawai, R.J. Geller, K. Konishi
    • Journal Title

      Physics of the Earth and Planetary Interiors

      Volume: 282 Pages: 117-143

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] What is the origin of macroscopic friction?2018

    • Author(s)
      Sakuma, H., K. Kawai, I. Katayama, S. Suehara
    • Journal Title

      Science Advances

      Volume: 4 Issue: 12 Pages: 1-6

    • DOI

      10.1126/sciadv.aav2268

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] High-pressure phase transitions of anorthosite crust in the Earth’s deep mantle2017

    • Author(s)
      Nishi M., Greaux S., Tateno S., Kuwayama Y., Kawai K., Irifune T., Maruyama S.
    • Journal Title

      Geoscience Frontiers

      Volume: in press Issue: 6 Pages: 1-13

    • DOI

      10.1016/j.gsf.2017.10.002

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Presentation] Mantle flows in the lowermost mantle beneath the Northern Pacific inferred by 3-D waveform inversion for radially anisotropic structure2020

    • Author(s)
      鈴木 裕輝, 河合 研志, ゲラー ロバート
    • Organizer
      日本地球惑星科学連合大会
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Imaging subducted slabs in the mantle through inversion of seismic waveforms2020

    • Author(s)
      河合 研志, Borgeaud Anselme, 鈴木 裕輝, ゲラー ロバート
    • Organizer
      日本地球惑星科学連合大会
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Seismic structure near the inner core boundary in the north polar region2020

    • Author(s)
      大滝 壽樹, 田中 聡, 金嶋 聰, Siripunvaraporn Weerachai, Boonchaisuk Songkhun, Noisagool Sutthipong, 河合 研志, Kim Taewoon, 鈴木 裕輝, 石原 靖, 宮川 幸治, 竹内 希, 川勝 均
    • Organizer
      日本地球惑星科学連合大会
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Interaction and Coevolution of the Core and Mantle in the Earth and Planets2019

    • Author(s)
      Kenji Kawai, Tsuyoshi Iizuka, Kenji Ohta, Taku Tsuchiya
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] Waveform inversion for 3D anisotropic structure in D" beneath the Northern Pacific: Constraints on mineralogy and flow in the lowermost mantle2019

    • Author(s)
      Yuki Suzuki, Kenji Kawai, Robert J. Geller
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] Detailed 3-D S-velocity structure within D" at the western Pacific LLSVP margin: smaller scale plumes and paleoslabs(Poster)2019

    • Author(s)
      Yuki Suzuki, Kenji Kawai, Robert J. Geller, Satoru Tanaka, Weerachai Siripuvaraporn, Songkhun Boonchaisuku, Noisagool Sutthipong, Yasushi Ishihara, Taweoon Kim, Koji Miyakawa, Nozomu Takeuchi
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] Origin and role of lost continents2019

    • Author(s)
      Shigenori Maruyama, Kenji Kawai, Greaux Steeve, Dapeng Zhao
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] 第一原理計算による層状鉱物gibbsiteの摩擦特性の研究(Poster)2019

    • Author(s)
      奥田 花也, 河合 研志, 佐久間 博
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] 3-D P- and S-velocity structure of the D″ layer beneath Central America and the Caribbean using waveform inversion2019

    • Author(s)
      Anselme F. E. Borgeaud, Kenji Kawai, Robert J. Geller
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Waveform inversion for the radial elastic and anelastic structure of the lowermost mantle beneath Central America and the Caribbean(Poster)2019

    • Author(s)
      Anselme F. E. Borgeaud, Frederic Deschamps, Kensuke Konishi, Kenji Kawai, Robert J. Geller
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] Waveform inversion for the radial elastic and anelastic structure of the lowermost mantle beneath Central America and the Caribbean2019

    • Author(s)
      Anselme F. E. Borgeaud, Frederic Deschamps, Kensuke Konishi, Kenji Kawai, Robert J. Geller
    • Organizer
      JpGU2019
    • Related Report
      2019 Research-status Report
  • [Presentation] Imaging subducted slabs in the mantle from inversion of seismic waves2019

    • Author(s)
      Kenji Kawai
    • Organizer
      International Workshop for Geophysical observation in Thailand Present and Future
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Imaging subducted slabs in the lowermost mantle from inversion of seismic waveforms2019

    • Author(s)
      Kenji Kawai, Anselme F.E. Borgeaud, Yuki Suzuki
    • Organizer
      2019年度 日本地球化学会年会
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Slip- and Velocity-Weakening Behaviors of Brucite Nanoparticle(Poster)2019

    • Author(s)
      H.Okuda, I.Katayama, H.Sakuma, K.Kawai
    • Organizer
      The 7th International Conference on Coupled THMC Processes
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Seismic structure near the inner core boundary in the north polar region2019

    • Author(s)
      Toshiki Ohtaki, Satoru Tanaka, Satoshi Kaneshima, Weerachai Siripunvarporn, Songkhun Boonchaisuk, Sutthipong Noisagool, Kenji Kawai, Taewoon Kim, Yuki Suzuki, Yasushi Ishihara, Koji Miyakawa, Nozomu Takeuchi and Hitoshi Kawakatsu
    • Organizer
      2019 AGU Fall Meeting
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] The Origin of Macroscopic Friction between Single Crystal Mica Surfaces2019

    • Author(s)
      Hiroshi Sakuma, Kenji Kawai, Ikuo Katayama, Shigeru Suehara
    • Organizer
      Second International Symposium on Crustal Dynamics(ISCD-2)
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] First-Principles Investigation for Frictional Characteristics of Brucite and its Application for Macroscopic Frictional Characteristics of Sheet-Structure Minerals2019

    • Author(s)
      Hanaya Okuda, Kenji Kawai, Hiroshi Sakuma, Ikuo Katayama
    • Organizer
      Second International Symposium on Crustal Dynamics(ISCD-2)
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] Sedimentary Records Of Ancient Mud Volcanism: How Do We Identify Mud Volcanoes In The Strattgraphy Of Mars?2019

    • Author(s)
      G. Komatsu, R. Ishimaru, K. Kawai, N. Miyake, M. Kobayashi, T. Matsui
    • Organizer
      50th Lunar and Planetary Science Conference in The Woodlands
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] 波形インバージョンによる北部太平洋下D”領域の3次元S波速度構造推定2018

    • Author(s)
      鈴木裕輝, 河合研志, Robert J. Geller
    • Organizer
      日本地震学会秋季大会
    • Related Report
      2018 Research-status Report
  • [Presentation] 震源時間関数の再決定が波形インバージョンによる3次元速度構造推定に与える影響の定量的評価2018

    • Author(s)
      山谷里奈, Anselme Borgeaud, 河合研志, Robert J. Geller, 小西健介
    • Organizer
      日本地震学会秋季大会
    • Related Report
      2018 Research-status Report
  • [Presentation] 西太平洋直下最下部マントルにおける3次元S波速度構造から見るイザナギプレートとLLSVP2018

    • Author(s)
      河合研志
    • Organizer
      新学術領域研究 核-マントルの相互作用と共進化~統合的地球深部科学の創成~A03-1地震・電磁気観測班の合同班会議
    • Related Report
      2018 Research-status Report

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Published: 2018-04-23   Modified: 2022-01-27  

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