コア・陸上・実験の統合による地震時の水-岩石反応の解明

• Project Area: New perspective of great subduction-zone earthquakes from the super deep drilling
• Project/Area Number: 22107505
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo
• Principal Investigator: 山口 飛鳥 東京大学, 大学院・理学系研究科, 特任研究員 (30570634)
• Project Period (FY): 2010 – 2011
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2011: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2010: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 沈み込み帯 / 地震発生帯 / 付加体 / IODP / NanTroSEIZE / 四万十帯 / 微量元素組成 / IODO / 高速摩擦実験

Research Abstract

平成24年度は以下の研究を行った。
1.南海トラフ分岐断層浅部から得られたのコア試料のXRFコアロガーを用いた主要・微量元素組成分析結果の解析から、すべり面において選択的にスメクタイトのイライト化反応が起こっていることを示し、分岐断層における地震時のすべりが浅部まで到達した可能性を指摘した論文をGeology誌に発表した。これは2011年東北地方太平洋沖地震で見られたような浅部に達する巨大すべりが南海トラフでも起こっていたことを示す成果である。
2.沈み込み初期物質が地震時の水-岩石反応に果たす影響を評価するため、南海トラフ海溝外側で得られた遠洋性堆積物・玄武岩コア試料の薄片作成を行い、微細スケールの続成・変質・変形組織に関する解析を行った。
3.四万十帯延岡衝上断層・槇峰層、美濃帯犬山地域の岩石試料採取を行うとともに、沈み込み帯の流体組成の解析のため、中部地方の深部起源非火山性流体のサンプリングを行った。
4.上記2.で得られたコア試料、3.で採取した陸上の断層岩・鉱物脈・流体試料の化学分析を行った。断層岩は主要・微量元素組成をXRFおよびICP-MSで測定し、Li,Sr同位体組成についてはMC-ICP-MSおよびTIMSを用いた。鉱物脈中の流体包有物、および流体試料・実験生成試料にういては、主成分元素組成はICP-AESで、微量元素組成・同位体組成についてはMC-ICP-MSおよびTIMSで測定を行った。
5.2010年5月/日本地球惑星連合大会、9月/IODP NanTroSEIZE Stage2ポストクルーズ会議、12月/アメリカ地球物理学連合秋季大会、3月/新学術領域国際研究集会およびアメリカ地質学会ペンローズ会議において、到達状況を報告した。また、上記4に関する研究成果についてGeochemistry,Geophysics,Geosystems誌に論文を投稿した。

Research Products

• [Journal Article] Silica diagenesis and its effect on interplate seismicity in cold subduction zones (2012)
  • Author(s): Jun Kameda
  • Journal Title: Earth and Planetary Science Letters Volume: 317-318 Pages: 136-144
  • DOI: 10.1016/j.epsl.2011.11.041
  • Peer Reviewed
• [Journal Article] Tectonic melange as fault rock of subduction plate boundary (2012)
  • Author(s): Gaku Kimura
  • Journal Title: Tectonophysics Volume: (In press) Pages: 25-38
  • DOI: 10.1016/j.tecto.2011.08.025
  • Peer Reviewed
• [Journal Article] Seismic slip propagation to the up-dip end of plate boundary subduct ion interface faults : Vitrinite reflectance geothermometry on Integrated Ocean Drilling Program NanTroSEIZE cores (2011)
  • Author(s): Sakaguchi, Arito
  • Journal Title: Geology Volume: 39 Issue: 4 Pages: 395-399
  • DOI: 10.1130/g31642.1
  • Peer Reviewed
• [Journal Article] Progressive illitization in fault gouge caused by seismic slip propagation along a megasplay fault in the Nankai Trough (2011)
  • Author(s): Yamaguchi, A., Sakaguchi, A., Sakamoto, T., Iijima, K., Kameda, J., Kimura, G., Ujiie, K., Chester, F.M., Fabbri, O., Goldsby, D., Tsutsumi, A., Li, C.-F., Curewitz, D.
  • Journal Title: Geology Volume: 39 Issue: 11 Pages: 995-998
  • DOI: 10.1130/g32038.1
  • Peer Reviewed
• [Journal Article] A new source of water in seismogenic subduction zones (2011)
  • Author(s): Kameda, J., Yamaguchi, A., Saito, S., Sakuma, H., Kawamura, K., Kimura, G.
  • Journal Title: Geophysical Research Letters Volume: 38 Issue: 22 Pages: n/a-n/a
  • DOI: 10.1029/2011gl048883
  • Peer Reviewed
• [Journal Article] Dynamic changes in fluid redox state associated with episodic fault rupture along a megasplay fault in a subduction zone (2011)
  • Author(s): Yamaguchi, A.
  • Journal Title: Earth Planetary Science Leters Volume: 302 Pages: 369-377
  • Peer Reviewed
• [Journal Article] Geological record of thermal pressurization and earthquake instability of subduction thrusts (2010)
  • Author(s): Ujiie, K
  • Journal Title: Tectonophysics Volume: 485 Pages: 260-268
  • Peer Reviewed
• [Journal Article] Record of mega-earthquakes in subduction thrusts : the black fault rocks of Pasagshak Point (Kodiak Island, Alaska) (2010)
  • Author(s): Meneghini, F.
  • Journal Title: Geological Society of America Bulletin Volume: 122 Pages: 1280-1297
  • Peer Reviewed
• [Journal Article] 小学生向け地震・津波発生装置の製作とその教育実践 (2010)
  • Author(s): 香月興太
  • Journal Title: 地学教育 Volume: 63 Pages: 135-147
  • Peer Reviewed
• [Presentation] Alteration of uppermost oceanic crust and its effect on deformations in subduction zones (2012)
  • Author(s): Asuka Yamaguchi
  • Organizer: The Geological Sosiety of America Penrose Conference on Deformation, Fluid Flow, and Mass Transfer in the Forearc of Convergent Margins
  • Place of Presentation: Il Ciocco, Castelvecchio Pascoli, Lucca, Italy
  • Year and Date: 2012-03-28
• [Presentation] Continuous coring and logging dataset from fossilized megasplay fault : project overview and preliminary results of the Nobeoka Thrust Drilling Project (NOBELL) (2012)
  • Author(s): Asuka Yamaguchi
  • Organizer: International Conference on a New Perspective of Great Earthquakes along Subduction Zones
  • Place of Presentation: 高知県高知市文化プラザかるぽーと
  • Year and Date: 2012-02-28
• [Presentation] Alteration process of subducting basalt and its role for rheology and mass flux along subduction thrust (2012)
  • Author(s): Asuka Yamaguchi
  • Organizer: International Conference on a New Perspective of Great Earthquakes along Subduction Zones
  • Place of Presentation: 高知県高知市文化プラザかるぽーと
  • Year and Date: 2012-02-28
• [Presentation] The deformation structure of submarine landslide recorded in the incoming sediments on the Kashinosaki Knoll, in the Nankai Trough (2011)
  • Author(s): Bora Song
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-09
• [Presentation] Water supplement by silica diagenesis in cold subduction zone : an implication for the Japan Trench (2011)
  • Author(s): Shoko Hina
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-06
• [Presentation] Silica diagenesis and its effect oh interplate seismicity in cold subduction zones (2011)
  • Author(s): Jun Kameda
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-06
• [Presentation] Progressive illitization in fault gouge caused by seismic slip propagation along a megasplay fault in the Nankai Trough (2011)
  • Author(s): Asuka Yamaguchi
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-05
• [Presentation] A runaway slip to the trench due to breaking through abnormally pressurized megathrust under the middle trench slope-The tsunamigenesis of the 2011 Tohoku earthquake- (2011)
  • Author(s): Gaku Kimura
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-05
• [Presentation] Change in stress with seismic cycles identified at an out of sequence thrust in an on-land accretionary complex : The Nobeoka thrust, Shimanto Belt, Kyusyu, SW Japan (2011)
  • Author(s): Mika Yamaguchi
  • Organizer: 2011 AGU fall meeting
  • Place of Presentation: Moscone Convention Center, San Francisco, USA
  • Year and Date: 2011-12-05
• [Presentation] Anatomy of a thick (~70m) submarine land slide discovered at Kashinozaki Knoll in the Nankai Trough (2011)
  • Author(s): Asuka Yamaguchi
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-25
• [Presentation] 沈み込み帯におけるシリカ続成過程のシミュレーションと美濃帯犬山地域における層状チャートの続成過程への制約 (2011)
  • Author(s): 比名祥子
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-25
• [Presentation] 陸上付加体アウトオブシークエンススラストにおける応力変化:九州四万十帯延岡スラスト (2011)
  • Author(s): 山口実華
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-25
• [Presentation] 延岡衝上断層の破砕帯でみられる剪断集中帯とその周辺の微視的解析 (2011)
  • Author(s): 浜橋真理
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-25
• [Presentation] NanTroSEIZE Site C0012における海洋底玄武岩最上部の変質パターンと沈み込みプレート境界断層のレオロジー (2011)
  • Author(s): 山口飛鳥
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-24
• [Presentation] 熊野灘沖付加体巨大分岐断層とプレート境界断層の表層まで伝播した地震破壊-IODP Exp316ちきゅうによる非破壊コア分析の成果- (2011)
  • Author(s): 坂口有人
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-24
• [Presentation] スロースリップの物質的な証拠 (2011)
  • Author(s): 濱田洋平
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2011-05-24
• [Presentation] Thin hydrated oceanic crust can control rheology and seismicity of subduction plate boundary (2011)
  • Author(s): Asuka Yamaguchi
  • Organizer: NanTroSEIZE Stage2 2^<nd> post cruise meeting
  • Place of Presentation: ICM Barcelona, Spain
• [Presentation] 沈み込む玄武岩の変質履歴と底付け付加 (2010)
  • Author(s): 山口飛鳥
  • Organizer: 日本地質学会第117年学術大会
  • Place of Presentation: 富山大学
  • Year and Date: 2010-09-19
• [Presentation] Co-seismic chemical reactions in seismogenic subduction zones : field, geochemical and experimental approaches (2010)
  • Author(s): Yamaguchi, A.
  • Organizer: Joint Meeting of Korean and Japanese Geological Societies
  • Place of Presentation: Muroto, Kochi
  • Year and Date: 2010-08-24
• [Presentation] Fluctuations in redox state along seismogenic megasplay fault (2010)
  • Author(s): Yamaguchi, A
  • Organizer: Tohoku University Global COE Program, G-COE symposium 2010 : Dynamic Earth and Heterogeneous Structure
  • Place of Presentation: Tohoku University
  • Year and Date: 2010-07-13
• [Presentation] コディアク付加体Pasagshak Point thrustにおける地震時の水-岩石相互作用 (2010)
  • Author(s): 山口飛鳥
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2010-05-26
• [Presentation] 付加体深部の流体組成変動 (2010)
  • Author(s): 山口飛鳥
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉県幕張メッセ
  • Year and Date: 2010-05-25