Investigation of mantle electrical conductivity beneath the Tristan da Cunha hotspot in Atlantic Ocean by Japan-Germany collaboration

• Project/Area Number: 23403005
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Solid earth and planetary physics
• Research Institution: The University of Tokyo
• Principal Investigator: KIYOSHI Baba 東京大学, 地震研究所, 助教 (70371721)
• Co-Investigator(Renkei-kenkyūsha): UTADA Hisashi 東京大学, 地震研究所, 教授 (70134632)
• Research Collaborator: JEGEN-KULCSAR Marion キール大学, 海洋研究所(IFM-GEOMAR)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥19,110,000 (Direct Cost: ¥14,700,000、Indirect Cost: ¥4,410,000); Fiscal Year 2014: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2013: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2012: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2011: ¥10,010,000 (Direct Cost: ¥7,700,000、Indirect Cost: ¥2,310,000)
• Keywords: マントル / ホットスポット / トリスタン・ダ・クーニャ / 大陸分裂 / 電気伝導度 / MT法 / 海底電位磁力計 / 国際研究者交流 / マントルプルーム / 大西洋

Outline of Final Research Achievements

This research project aims to investigate the electrical structure of the mantle beneath the Tristan da Cunha hotspot in southern Atlantic Ocean to deepen the knowledge of the hotspot source. This is a collaborative study between Japanese and German research groups. The seafloor electromagnetic observation was conducted for an year from January 2012 by using total 26 ocean bottom electromagnetometers. The time variation of the natural electromagnetic field was measured and analyzed to obtain electromagnetic response functions which have information of Earth's electrical conductivity. The quality of observed data were good for most of the stations. Further inversion analysis of the response functions will enable us to image a three-dimensional electrical conductivity structure beneath the observation area.

Research Products

• [Journal Article] Three-dimensional inversion of seafloor magnetotelluric data collected in the Philippine Sea and the western margin of the northwest Pacific Ocean (2014)
  • Author(s): Noriko Tada, Kiyoshi Baba, Hisashi Utada
  • Journal Title: Geochemistry, Geophysics, Geosystems Volume: 15 Issue: 7 Pages: 2895-2917
  • DOI: 10.1002/2014gc005421
  • Peer Reviewed
• [Journal Article] Estimating the electrical conductivity of the melt phase of a partially molten asthenosphere from seafloor magnetotelluric sounding data (2014)
  • Author(s): Utada, H, Baba, K.
  • Journal Title: Phys. Earth Planet. Inter. Volume: 227 Pages: 41-47
  • DOI: 10.1016/j.pepi.2013.12.004
  • Peer Reviewed
• [Journal Article] Practical incorporation of local and regional topography in three-dimensional inversion of deep ocean magnetotelluric data (2013)
  • Author(s): Kiyoshi Baba
  • Journal Title: Geophys. J. Int. Volume: 194 Issue: 1 Pages: 348-361
  • DOI: 10.1093/gji/ggt115
  • Peer Reviewed
• [Journal Article] Is the electrical conductivity of the northwestern Pacific upper mantle normal? (2013)
  • Author(s): Baba, K., N. Tada, L. Zhang, P. Liang, H. Shimizu, and H. Utada
  • Journal Title: Geochem. Geophys. Geosyst. Volume: 14 Issue: 12 Pages: 4969-4979
  • DOI: 10.1002/2013gc004997
  • Peer Reviewed
• [Journal Article] 高速拡大中央海嶺下の電気伝導度構造とマントルダイナミクス (2012)
  • Author(s): 馬場聖至
  • Journal Title: 月刊地球 Volume: 34 Pages: 231-235
• [Journal Article] Approximate treatment of seafloor topographic effects in three-dimensional marine magnetotelluric inversion
  • Author(s): Tada, N., Baba, K., Utada, H., Siripunvaraporn, W.
  • Journal Title: Earth, Planets and Space Volume: (印刷中)
  • NAID: 10031141572
  • Peer Reviewed
• [Presentation] 「ふつう」の海洋マントルの電気伝導度構造イメージング (2015)
  • Author(s): 馬場聖至, 多田訓子, 松野哲男, 梁朋飛, 張羅磊, 清水久芳, 歌田久司
  • Organizer: 日本地球惑星科学連合2015年大会
  • Place of Presentation: 幕張メッセ（千葉県千葉市）
  • Year and Date: 2015-05-24 – 2015-05-28
• [Presentation] マントル電気伝導度構造の定量的解釈 (2015)
  • Author(s): 馬場聖至
  • Organizer: 本地球惑星科学連合2015年大会
  • Place of Presentation: 幕張メッセ（千葉県千葉市）
  • Year and Date: 2015-05-24 – 2015-05-28
• [Presentation] Geothermal and compositional variety of old oceanic upper mantle in northwestern Pacific: Insights from seafloor magnetotelluric experiments (2014)
  • Author(s): Baba, K., Utada, H., Tada, N., Shimizu, H., Zhang, L., and Liang, P.
  • Organizer: AGU 2014 fall meeting
  • Place of Presentation: アメリカ合衆国・サンフランシスコ
  • Year and Date: 2014-12-15 – 2014-12-19
• [Presentation] 年代に伴う海洋マントル冷却モデルと北西太平洋の電気伝導度 (2014)
  • Author(s): 馬場聖至, 多田訓子, 梁朋飛, 張羅磊, 清水久芳, 歌田久司
  • Organizer: 第136回地球電磁気・地球惑星圏学会講演会
  • Place of Presentation: キッセイ文化ホール（長野県松本市）
  • Year and Date: 2014-10-31 – 2014-11-03
• [Presentation] Thermal and compositional variety of old oceanic upper mantle in northwestern Pacific revealed from marine magnetotelluric experiments (2014)
  • Author(s): Baba, K., Tada, N., Liang, P., Zhang, L., Shimizu, H., and Utada, H.
  • Organizer: 22nd International Workshop on Electromagnetic Induction of the Earth
  • Place of Presentation: ドイツ・ワイマール
  • Year and Date: 2014-08-24 – 2014-08-30
• [Presentation] 海洋アセノスフェアの電気伝導度 (2014)
  • Author(s): 馬場聖至
  • Organizer: CA研究会
  • Place of Presentation: 東京・東京大学地震研究所
• [Presentation] ふつうの海洋マントルの電気伝導度（第二報） (2014)
  • Author(s): 馬場聖至, 歌田久司, 清水久芳, 張羅磊, 梁朋飛, 多田訓子
  • Organizer: Blue Earth 2014
  • Place of Presentation: 東京・東京海洋大学
• [Presentation] 古い海洋上部マントルの温度構造：北西太平洋における電気伝導度構造イメージングからの制約 (2014)
  • Author(s): 馬場聖至, 多田訓子, 梁朋飛, 張羅磊, 清水久芳, 歌田久司
  • Organizer: 日本地球惑星科学連合2014年大会
  • Place of Presentation: 神奈川・パシフィコ横浜会議センター
  • Invited
• [Presentation] 普通の海洋マントルの電気伝導度構造イメージング（序報） (2013)
  • Author(s): 馬場聖至, 歌田久司, 多田訓子, 清水久芳
  • Organizer: 日本地球惑星科学連合2013年大会
  • Place of Presentation: 千葉・幕張メッセ
• [Presentation] 電気伝導度構造が示唆するプチスポットメルトの起源 (2013)
  • Author(s): 馬場聖至, 阿部なつ江, 平野直人, 市來雅啓
  • Organizer: 日本地球惑星科学連合2013年大会
  • Place of Presentation: 千葉・幕張メッセ
• [Presentation] Electrical lithosphere and asthenosphere beneath “normal” ocean floor in northwestern Pacific (2013)
  • Author(s): Baba, K., H. Utada, N. Tada, L. Zhang, P. laing and H. Shimizu
  • Organizer: AGU 2013 fall meeting
  • Place of Presentation: アメリカ合衆国・サンフランシスコ
• [Presentation] ふつうの海洋マントルの電気伝導度（序報） (2013)
  • Author(s): 馬場聖至, 歌田久司, 多田訓子
  • Organizer: Blue Earth 2013
  • Place of Presentation: 東京・東京海洋大学
• [Presentation] Practical incorporation of topography in three-dimensional inversion of marine magnetotelluric data (2012)
  • Author(s): Baba, K., N. Tada, H. Utada, and W. Siripunvaraporn
  • Organizer: 21st International Workshop on Electromagnetic Induction of the Earth
  • Place of Presentation: オーストラリア・ダーウィン
• [Presentation] 北西太平洋プチスポット周辺海域の3次元上部マントル電気伝導度構造 (2012)
  • Author(s): 馬場聖至, 阿部なつ江, 平野直人, 市來雅啓
  • Organizer: 第132回地球電磁気・地球惑星圏学会講演会
  • Place of Presentation: 北海道・札幌コンベンションセンター
• [Presentation] Electromagnetic constraints on the structure of the oceanic upper-mantle : Consistencies and inconsistencies with other observations (2011)
  • Author(s): Evans, R.L., Lizarralde, D., Collins, J.A., Elsenbeck, J., Tursack, E., Hirth, G., Gaherty, J.B., Pommier, A., Baba, K., Matsuno, T.
  • Organizer: AGU fall meeting 2011
  • Place of Presentation: 米国・サンフランシスコ(招待講演)
  • Year and Date: 2011-12-07
• [Presentation] ソサエティー・ホットスポットの海底アレイ観測によるトモグラフィー研究(TIARES)計画:海底電磁気観測の速報 (2011)
  • Author(s): 多田訓子, 笠谷貴史, 馬場聖至, 浜野洋三, 阿部なつ江, 末次大輔
  • Organizer: 第130回地球電磁気・地球惑星圏学会講演会
  • Place of Presentation: 兵庫・神戸大学(神戸市)
  • Year and Date: 2011-11-05
• [Presentation] 高速拡大中央海嶺下の電気伝導度構造 (2011)
  • Author(s): 馬場聖至, Chave, A.D., Evans, R.L., Tarits, P., Hirth, G., Mackie, R.L.
  • Organizer: 日本地質学会第118年学術大会・日本鉱物科学会2011年年会合同学術大会
  • Place of Presentation: 茨城市茨城大学(招待講演)
  • Year and Date: 2011-09-09
• [Presentation] Marine magnetotelluric study on petit-spot volcanism in northwestern Pacific (2011)
  • Author(s): Baba, K., Abe, N.
  • Organizer: AOGS 2011
  • Place of Presentation: 台湾・台北(招待講演)
  • Year and Date: 2011-08-09
• [Presentation] 海底地形効果の3次元海底MTインバージョンへの組込み (2011)
  • Author(s): 多田訓子, 馬場聖至, 歌田久司
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉市幕張メッセ
  • Year and Date: 2011-05-26
• [Presentation] A discussion on the cause of high electrical conductivity in the oceanic upper mantle (2011)
  • Author(s): Utada, H., Baba, K.
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉市幕張メッセ(招待講演)
  • Year and Date: 2011-05-25
• [Presentation] Ocean bottom geophysical observation on the seafloor near the Society hot spot, Frech Polynesia (2011)
  • Author(s): Suetsugu, D., Shiobara, H., Sugioka, H., Ito A., Isse, T, Baba, K., Kasaya, T., Tada, N.
  • Organizer: 日本地球惑星科学連合2011年大会
  • Place of Presentation: 千葉市幕張メッセ
  • Year and Date: 2011-05-25
• [Presentation] Electrical conductivity of old oceanic mantle beneath the northwestern Pacific revealed from seafloor magnetotelluric observations (2011)
  • Author(s): Baba, K., Utada,H., Abe, N.
  • Organizer: EGU General Assembly 2011
  • Place of Presentation: オーストリア・ウィーン
  • Year and Date: 2011-04-06
• [Presentation] Ocean bottom geophysical observation on the seafloor near the Society hot spot, Frech Polynesia (2011)
  • Author(s): Suetsugu, D., Shiobara, H., Isse, T., Sugioka, H., Ito A., Baba, K., Kasaya, T., Tada, N.
  • Organizer: EGU General Assembly 2011
  • Place of Presentation: オーストリア・ウィーン
  • Year and Date: 2011-04-06