Imaging the stagnant slab by ocean bottom electromagnetic observation

2008 Fiscal Year Final Research Report

• Project/Area Number: 16075204
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo
• Principal Investigator: UTADA Hisashi The University of Tokyo, 地震研究所, 教授 (70134632)
• Co-Investigator(Renkei-kenkyūsha): UYESHIMA Makoto 東京大学, 地震研究所, 准教授 (70242154) ; SHIMIZU Hisayoshi 東京大学, 地震研究所, 助教授 (70302619) ; KOYAMA Takao 東京大学, 地震研究所, 助教授 (00359192) ; TOH Hiroaki 京都大学, 大学院・理学研究科, 准教授 (40207519) ; GOTO Tadanori 京都大学, 大学院・工学研究科, 准教授 (90303685) ; KASAYA Takafumi 海洋研究開発機構, 地球内部変動研究センター, 研究員 (90373456)
• Research Collaborator: TADA Noriko 海洋研究開発機構, 地球内部変動研究センター, 研究員 (00509713)
• Project Period (FY): 2004 – 2008
• Keywords: 地球深部スラブ / 地球電磁気観測 / 電気伝導度 / マントル遷移層 / 水 / 海底電磁力計 / フィリピン海 / 電磁気トモグラフィー

Research Abstract

2005年秋から2008年秋までの3年間にわたり,フィリピン海において海底電磁気機動観測を行なった.1年間の設置を3回繰り返し,のべ39箇所の観測とデータ取得をほぼ完全に達成した.また,既存の西太平洋地域の地磁気観測所データ・海底ケーブル電位差データの解析を進め,太平洋マントルの平均的電気伝導度モデルを更新した.海底機動観測データの解析により,フィリピン海の上部マントルおよび遷移層は太平洋やヨーロッパに比べて有意に高電気伝導度であることがわかった.

Research Products

• [Journal Article] A joint interpretation of electromagnetic and seismic tomography models suggests the mantle transition zone below Europe is dry (2009)
  • Author(s): Utada, H., Koyama, T., Obayashi, M., Fukao, Y.
  • Journal Title: Earth Planet. Sci. Lett. 281 Pages: 249-257
  • Peer Reviewed
• [Journal Article] Ocean Bottom Array Probes Stagnant Slab Beneath the Philippine Sea, EOS (2009)
  • Author(s): Shiobara, H., K. Baba, H. Utada and Y. Fukao
  • Journal Title: Trans. AGU 90, No.9 Pages: 70-71
  • Peer Reviewed
• [Journal Article] 1-D electrical conductivity structure beneath the Philippine Sea: Results from an ocean bottom magnetotelluric survey (2007)
  • Author(s): Seama, N., K. Baba, H. Utada , H. Toh, N. Tada, M. Ichiki and T. Matsuno
  • Journal Title: Phys. Earth Planet. Inter. 162 Pages: 2-12
  • Peer Reviewed
• [Journal Article] Content in the Mantle Transition Zone Beneath the North Pacific Derived From the Electrical Conductivity Anomaly (2006)
  • Author(s): Koyama, T., H. Shimizu, H. Utada, M. Ichiki, E. Ohtani, and R. Hae, Water
  • Journal Title: AGU Geophys. Monogr. Ser. 168 Pages: 171-179
  • Peer Reviewed
• [Journal Article] Water content and geotherm in the upper mantle above the stagnant slab : Interpretation of electrical conductivity and seismic P-wave velocity models (2006)
  • Author(s): Ichiki, M., K. Baba, M. Obayashi and H. Utada
  • Journal Title: Phys. Earth Planet. Inter. 155 Pages: 1-15
  • Peer Reviewed
• [Journal Article] 3-D modelling and analysis of Dst C -responses in the North Pacific Ocean region, revisited (2005)
  • Author(s): Kuvshinov, A., H. Utada, D. Avdeev, and T. Koyama
  • Journal Title: Geophys. J. Int. 160 Pages: 505-526
  • Peer Reviewed
• [Journal Article] Three-dimensional magnetotelluric inversion : data space method (2005)
  • Author(s): Siripunvaraporn, W., Egbert, G., Lenbury,Y. and Uyeshima, M.
  • Journal Title: Phys. Earth Planet. Int. 150 Pages: 3-14
  • Peer Reviewed
• [Journal Article] The feasibility of using decadal changes in the geoelectric field to probe Earth' s core (2004)
  • Author(s): Shimizu, H., and H. Utada
  • Journal Title: Phys. Earth Planet. Int. 142 Pages: 297-319
  • Peer Reviewed
• [Journal Article] Trans-pacific temperature field in the mantle transition region derived from seismic and electromagnetic tomography (2004)
  • Author(s): Fukao, Y., T. Koyama, M. Obayashi, and H. Utada
  • Journal Title: Earth Planet. Sci. Lett. 217 Pages: 425-534
  • Peer Reviewed
• [Presentation] Toward 3-D inversion of seafloor MT data collected by Stagnant Slab Project (2009)
  • Author(s): Tada, N., K. Baba, W. Siripunvaraporn, M. Uyeshima, and H. Utada
  • Organizer: Stagnant Slab Project International Symposium
  • Place of Presentation: Kyoto
  • Year and Date: 2009-02-26
• [Presentation] Semi-global and regional electrical conductivity models derived from inversion of electromagnetic variation data in the North Pacific Ocean and Philippine Sea (2009)
  • Author(s): Shimizu, H.
  • Organizer: Stagnant Slab Project International Symposium
  • Place of Presentation: Kyoto
  • Year and Date: 2009-02-25
• [Presentation] On one-dimensional mantle conductivity modeling of 3-dimensional Earth (2008)
  • Author(s): H. Utada, H. Shimizu, K. Baba, T. Koyama
  • Organizer: AGU 2008 Fall Meeting
  • Place of Presentation: San Francisco
  • Year and Date: 2008-12-15
• [Presentation] Three-dimensional geomagnetic response functions for global and semi-global scale induction problems (2008)
  • Author(s): Shimizu H., Koyama T., Baba K., Utada H.
  • Organizer: International Workshop on EM induction
  • Place of Presentation: Beijing
  • Year and Date: 2008-10-24
• [Presentation] Possible Observational constraints on lateral electrical conductivity contrast in the deep mantle (2008)
  • Author(s): H. Shimizu, H. Nagao, and H. Utada
  • Organizer: International Workshop on Transport Properties in the Lower Mantle
  • Place of Presentation: Yunishigawa
  • Year and Date: 2008-10-23
• [Presentation] Three dimensional geomagnetic response functions for global and semi-global scale induction problems (2008)
  • Author(s): H. Shimizu, T. Koyama, K. Baba, H. Utada
  • Organizer: 日本地球惑星科学連合2008年大会
  • Year and Date: 2008-05-27
• [Presentation] Challenge to image the stagnant slab beneath the Philippine Sea by seafloor electromagnetic survey (2007)
  • Author(s): Utada, H., K. Baba, T. Goto, T. Kasaya, T. Ichikita, N. Tada, H. Shimizu, T. Koyama, & M. Uyeshima
  • Organizer: AGU 2007 fall meeting
  • Year and Date: 2007-12-12
• [Presentation] 海底電磁気機動観測によりスタグナントスラブを診る-第一次観測の成果- (2007)
  • Author(s): 馬場聖至, 後藤忠徳, 笠谷貴史, 一北岳夫, 小山崇夫, 清水久芳, 多田訓子, 上嶋誠, 歌田久司
  • Organizer: 特定領域研究「地球深部スラブ」第3回研究シンポジウム
  • Year and Date: 2007-11-03
• [Presentation] A semi-global inversion of geomagnetic and geoelectric response functions (2007)
  • Author(s): Utada, H.
  • Organizer: IUGG XXIV General Assembly
  • Place of Presentation: Perugia, Italy
  • Year and Date: 2007-07-06
• [Presentation] Challenge to image deep mantle slab by seafloor electromagnetic survey (2007)
  • Author(s): Baba, K., T. Goto, T. Kasaya, T. Ichikita, T. Koyama, H. Shimizu, M. Uyeshima, & H. Utada
  • Organizer: IUGG XXIV General Assembly
  • Place of Presentation: Perugia, Italy
  • Year and Date: 2007-07-06
• [Presentation] First results of Network-MT survey in Central Japan (2006)
  • Author(s): Uyeshima, M., T. Ogawa, S. Koyama, S. Yamaguchi, H. Toh, H. Murakami, R. Yoshimura, N. Oshiman, T. Kasaya, T. Tanbo, & W. Siripunvaraporn
  • Organizer: The 18th IAGA Workshop on Electromagnetic Induction in the Earth
  • Place of Presentation: ElVendrell, Spain
  • Year and Date: 2006-09-23
• [Presentation] Electrical conductivity in the mantle transition zone beneath the northwestern Pacific : Implication for the presence of water, International Session (2006)
  • Author(s): H. Utada, T. Goto, T. Koyama, H. Shimizu, K. Baba
  • Organizer: 日本地球惑星科学連合2006年大会
  • Year and Date: 2006-05-15
• [Presentation] Electrical Conductivity In The Mantle Transition Zone Beneath The Northwestern Part of The Pacific And Its Implication For The Presence Of Water (2005)
  • Author(s): H. Utada, T. Goto, T. Koyama, H. Shimizu, M Obayashi, Y. Fukao
  • Organizer: AGU 2005 Fall Meeting
  • Place of Presentation: San Francisco
  • Year and Date: 2005-12-08
• [Presentation] Three-dimensional electrical conductivity structure in the mid-mantle beneath Europe estimated by GDS methods (2005)
  • Author(s): Koyama, T., H. Shimizu & H. Utada
  • Organizer: IAGA Scientific Assembly
  • Place of Presentation: Toulouse, France
  • Year and Date: 2005-07-20
• [Presentation] Water contents in the mantle transition zone beneath the north Pacific derived from the electrical conductivity anomaly (2005)
  • Author(s): Koyama, T., H. Shimizu, H. Utada, E. Ohtani & R. Hae
  • Organizer: IAGA Scientific Assembly
  • Place of Presentation: Toulouse, France
  • Year and Date: 2005-07-20
• [Presentation] An ocean bottom instrument with a 10 km-long cable for long-term measurement of geo-electric field variations (2005)
  • Author(s): H. Utada, H. Shimizu, K. Kawaguchi, T. Goto
  • Organizer: IAGA General Assembly
  • Place of Presentation: Toulouse, France
  • Year and Date: 2005-07-20
• [Presentation] Water contents in the mantle transition zone beneath the north Pacific derived from the electrical conductivity anomaly (2004)
  • Author(s): Koyama, T., H. Shimizu, H. Utada, E. Ohtani & R. Hae
  • Organizer: American Geophysical Union Fall Meeting
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2004-12-15
• [Presentation] マリアナ沈み込み帯上部マントルの電気伝導度構造(1)2001-2002年海底MT観測の成果 (2004)
  • Author(s): 馬場聖至, 後藤忠徳, 島伸和, 市來雅啓, 歌田久司, 末広潔
  • Organizer: 地球惑星科学関連学会2004年合同大会
  • Place of Presentation: 千葉
  • Year and Date: 2004-05-11
• [Remarks]
  • URL: http://eri-ndc.u-tokyo.ac.jp/jp/ohrc/index.html