Estimation of stress state and detailed structure of the shallow plate boundary based on 3D active-source seismic data

• Project/Area Number: 18K13641
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Arai Ryuta 国立研究開発法人海洋研究開発機構, 海域地震火山部門(地震発生帯研究センター), 副主任研究員 (20738752)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 3D地震探査 / プレート沈み込み帯 / P波速度異方性 / 津波地震 / 波形インバージョン解析

Outline of Final Research Achievements

To reveal the physical and frictional properties of the shallow part of the plate boundary, I constructed a three-dimensional (3D) anisotropic P-wave velocity (Vp) structure model in the northern Hikurangi margin, New Zealand, by applying a traveltime tomography analysis to 3D seismic refraction data. The Vp model shows that significant anisotropic features occur in the vicinity of active branching faults in the accretionary wedge and the plate boundary. The fast axes of Vp are consistent with the direction of the plate convergence and thus reflect the compressional stress regime caused by the subduction. On the other hand, it rotates to the trench-parallel direction on the landward side of the forearc basin, which suggests that the coupling condition at the plate boundary and fault structures in the overriding plate may change at this location.

Academic Significance and Societal Importance of the Research Achievements

本研究により、プレート境界浅部の地震波速度異方性がプレート境界の応力状態やすべり様式、断層構造と密接に関係することがわかった。その学術的な意義が認められ、本研究の成果を出版した国際学術論文はEditors' Highlightsに選出され、高い評価を受けた。本研究と同様のデータ解析を日本周辺を含む他の沈み込み帯に適用することで、プレート境界浅部の実態とそこで発生する地震活動に関する理解がさらに進むと考えられる。

Research Products

• [Int'l Joint Research] Imperial College London(英国)
• [Int'l Joint Research] GNS Science(ニュージーランド)
• [Int'l Joint Research] University of Texas(米国)
• [Int'l Joint Research] Imperial College London(英国)
• [Int'l Joint Research] GNS Science(ニュージーランド)
• [Int'l Joint Research] University of Texas(米国)
• [Int'l Joint Research] Imperial College London(英国)
• [Int'l Joint Research] GNS Science(ニュージーランド)
• [Int'l Joint Research] University of Texas(米国)
• [Journal Article] Three‐Dimensional P Wave Velocity Structure of the Northern Hikurangi Margin From the NZ3D Experiment: Evidence for Fault‐Bound Anisotropy (2020)
  • Author(s): Arai Ryuta, Kodaira Shuichi, Henrys Stuart, Bangs Nathan, Obana Koichiro, Fujie Gou, Miura Seiichi, Barker Daniel, Bassett Dan, Bell Rebecca, Mochizuki Kimihiro, Kellett Richard, Stucker Valerie, Fry Bill, NZ3D Team
  • Journal Title: Journal of Geophysical Research: Solid Earth Volume: 125 Issue: 12
  • DOI: 10.1029/2020jb020433
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Estimation of stress state and detailed structure at shallow plate boundary based on 3D seismic data (2020)
  • Author(s): Arai Ryuta
  • Journal Title: Impact Volume: 2020 Issue: 3 Pages: 20-22
  • DOI: 10.21820/23987073.2020.3.20
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] New Zealand 3D Full Waveform Inversion (NZ3D-FWI) 2017-2018 Field Acquisition Report (2019)
  • Author(s): Bell, R. M. Gray, J. Morgan, M. Warner, A. Fagereng, L. McNeill, K. Jacobs, S. A. Henrys, B. Fry, S. Watkins, H. Lacey, J. A. Black, V. Lane, D. Daly, D. Lindsay, N. Bangs, R. Arai, S. Kodaira, NZ3D-FWI Team
  • Journal Title: GNS Science Report Volume: 71
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Recycling of depleted continental mantle by subduction and plumes at the Hikurangi Plateau large igneous province, southwestern Pacific Ocean (2019)
  • Author(s): Mochizuki K.、Sutherland R.、Henrys S.、Bassett D.、Van Avendonk H.、Arai R.、Kodaira S.、Fujie G.、Yamamoto Y.、Bangs N.、Barker D.
  • Journal Title: Geology Volume: 47 Issue: 8 Pages: 795-798
  • DOI: 10.1130/g46250.1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] 地震波構造探査に基づくプレート境界域の地震学的構造と地殻活動の研究 (2019)
  • Author(s): 新井隆太
  • Journal Title: 地震 Volume: 72 Pages: 1-16
  • NAID: 130007651932
  • Peer Reviewed / Open Access
• [Journal Article] The NZ3D Experiment - Adding a new dimension for understanding slow slip events (2018)
  • Author(s): MGL1801 Participants - Ryuta Arai, Stephen Ball, Nathan Bangs, Dan Barker, Joel Edwards, Melissa Gray, Shuoshuo Han, Harold Leah, Tim Reston, Hannah Tilley, and Harold Tobin
  • Journal Title: GeoPRISMS Newsletters Volume: 40 Pages: 14-15
  • Open Access / Int'l Joint Research
• [Presentation] P-wave velocity structure and stress state of shallow subduction faults in the northern Hikurangi margin, New Zealand, from NZ3D OBS data (2020)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Stuart Henrys, Nathan Bangs, Koichiro Obana, Gou Fujie, Seiichi Miura, Dan Barker, Dan Bassett, Rebecca Bell, Kimihiro Mochizuki, Richard Kellett, Valerie Stucker, Bill Fry, NZ3D team
  • Organizer: AGU Fall Meeting 2020
  • Int'l Joint Research
• [Presentation] Seismic evidence for fault-bound anisotropy and its implications on fault structure in the northern Hikurangi subduction zone (2020)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Stuart Henrys, Nathan Bangs, Koichiro Obana, Gou Fujie, Seiichi Miura, Dan Barker, Dan Bassett, Rebecca Bell, Kimihiro Mochizuki, Richard Kellett, Valerie Stucker, Bill Fry, NZ3D team
  • Organizer: JpGU-AGU Joint Meeting 2020
  • Int'l Joint Research
• [Presentation] ヒクランギ沈み込み帯北部プレート境界浅部周辺の P波異方性構造 (2019)
  • Author(s): 新井隆太、小平秀一、Henrys Stuart、Bangs Nathan、尾鼻浩一郎、藤江剛、三浦誠一、Bassett Dan、Barker Dan、Bell Rebecca、望月公廣、NZ3D Team
  • Organizer: 日本地震学会2019年度秋季大会
• [Presentation] Three-dimensional seismic structure of the shallow plate boundary in the northern Hikurangi margin from NZ3D OBS data (2019)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Richard Kellett, Valerie Stucker, Dan Bassett, Stuart Henrys, Koichiro Obana, Nathan Bangs, Dan Barker, Rebecca Bell, Kimihiro Mochizuki, Gou Fujie, Seiichi Miura, Bill Fry, NZ3D team
  • Organizer: 日本地球惑星科学連合2019年大会
  • Int'l Joint Research
• [Presentation] Three-dimensional anisotropic P-wave velocity structure around the shallow plate boundary in the Northern Hikurangi margin, New Zealand (2019)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Stuart Henrys, Nathan Bangs, Koichiro Obana, Gou Fujie, Seiichi Miura, Dan Barker, Dan Bassett, Rebecca Bell, Joanna Morgan, Mike Warner, Kimihiro Mochizuki, Richard Kellett, Valerie Stucker, Bill Fry, NZ3D team
  • Organizer: American Geophysical Union Fall Meeting 2019
  • Int'l Joint Research
• [Presentation] Structural controls on shallow slow earthquakes: Implications from three-dimensional seismic structure of the Northern Hikurangi subduction zone, New Zealand (2019)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Stuart Henrys, Nathan Bangs, Koichiro Obana, Gou Fujie, Seiichi Miura, Dan Barker, Dan Bassett, Rebecca Bell, Joanna Morgan, Mike Warner, Kimihiro Mochizuki, Richard Kellett, Valerie Stucker, Bill Fry, NZ3D team
  • Organizer: International Joint Workshop on Slow Earthquakes 2019
  • Int'l Joint Research
• [Presentation] ニュージーランドヒクランギ沈み込帯における地震波構造探査・自然地震観測 (2019)
  • Author(s): 新井隆太・小平秀一・藤江剛・尾鼻浩一郎・山本揚二朗・三浦誠一・望月公廣・仲谷幸浩・Stuart Henrys・Dan Barker・Richard Kellett・Dan Bassett・Nathan Bangs・Harm van Avendonk
  • Organizer: ブルーアースサイエンス・テク2019
• [Presentation] 地震波構造探査に基づくプレート境界域の地震学的構造と地殻活動の研究 (2018)
  • Author(s): 新井隆太
  • Organizer: 日本地震学会2018年秋季大会
  • Invited
• [Presentation] Summary of NZ3D (2018)
  • Author(s): Ryuta Arai
  • Organizer: Mini-Workshop at AGU -Investigating subduction processes at the Hikurangi margin, New Zealand-
  • Int'l Joint Research / Invited
• [Presentation] NZ3D OBS experiment: Toward elucidating high-resolution plate boundary structure, offshore Gisborne, Hikurangi margin, New Zealand (2018)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Richard L Kellett, Valerie K Stucker, Dan Bassett, Stuart A Henrys, Koichiro Obana, Nathan L Bangs, Daniel H N Barker, Rebecca E Bell, Kimihiro Mochizuki, Seiichi Miura, Bill Fry, NZ3D team
  • Organizer: AGU fall meeting
  • Int'l Joint Research
• [Presentation] Resolving Fine-Scale Velocity Structure of the Plate Boundary in the Northern Hikurangi Margin from the NZ3D OBS Survey (2018)
  • Author(s): Ryuta Arai, Shuichi Kodaira, Richard L Kellett, Valerie K Stucker, Dan Bassett, Stuart A Henrys, Koichiro Obana, Nathan L Bangs, Daniel H N Barker, Rebecca E Bell, Kimihiro Mochizuki, Seiichi Miura, Bill Fry, NZ3D team
  • Organizer: New Zealand Geosciences 2018
  • Int'l Joint Research
• [Presentation] NZプロジェクト －ヒクランギ沈み込帯での大規模海底地震観測－ (2018)
  • Author(s): 新井隆太・小平秀一 ・藤江剛・尾鼻浩一 郎・山本揚二朗・三浦誠一・ 望月公廣・ 仲谷幸浩・Stuart Henrys・Dan Barker・Richard Kellett・Dan Bassett・Nathan Bangs・Harm van Avendonk
  • Organizer: 日本地震学会2018年秋季大会
• [Remarks] 新井 隆太 副主任研究員らの論文がEditors' Highlightsに選出
  • URL: http://www.jamstec.go.jp/rimg/j/topics/20210115.html