地殻流体の電磁イメージング

2009 Fiscal Year Annual Research Report

• Project Area: Geofluids: Nature and dynamics of fluids in subduction zones
• Project/Area Number: 21109003
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: 小川 康雄 Tokyo Institute of Technology, 東京工業大学・火山流体研究センター, 教授 (10334525)
• Co-Investigator(Kenkyū-buntansha): 芳野 極 岡山大学, 地球物質科学研究センター, 准教授 (30423338) ; 藤田 清士 大阪大学, 工学系研究科, 講師 (00283862) ; 神田 径 京都大学, 防災研究所, 助教 (00301755) ; 小山 崇夫 東京大学, 地震研究所, 助教 (00359192) ; 藤 浩明 京都大学, 理学系研究科, 准教授 (40207519) ; 松島 政貴 東京工業大学, 大学院・理工学研究科, 助教 (20242266) ; 市來 雅啓 東京工業大学, 大学院・理工学研究科, 特別教育研究プロジェクト研究員 (80359182)
• Keywords: 地殻流体 / 電磁気観測 / 比抵抗 / 電気伝導度 / 地震 / 火山 / 高温高圧実験

Research Abstract

5カ年の研究目標は、沈み込み帯における流体相の3次元的な分布(Geofluid map)を、電磁気観測から解明することである。典型的な沈み込み帯である東北日本弧の中央部に位置する宮城県鳴子地域周辺で電磁気(MT : magneto-telluric)観測を高密度に行い、地殻・上部マントルの3次元比抵抗構造を推定する。また、比抵抗構造から流体の量と連結度を推定する為に、含水岩石の高温高圧実験を行う。さらにこれらの結果と、地震波トモグラフィーや粒界物性実験の結果を参考にして、Geofluid Mapを作成し、Geofluid Mapと岩石実験の結果をもとに地殻流体が地震火山活動に及ぼす影響を定量的に解明する。
今年度は、5カ年計画の第1年目である。まず、現有の広帯域電磁気観測機器を用いて、鬼首カルデラにおいて30観測点を3km間隔に面的に配置して観測した。3次元構造解析の結果、下部地殻から地殻上部の地熱地域までの流体の上昇域を解明することに成功した。また、次年度からの上部マントルを対象とする長周期電磁気観測のために、機材を導入するとともに、現有の長周期電磁気観測機器で、鳴子周辺の3地点において試験的な観測を開始した。さらに、地殻下部条件における含水岩石の比抵抗測定実験については、機材の整備を図るとともに、高温高圧下での含水岩石に類似した物質によるアナログ実験を開始した。また下部地殻条件下ではグラファイト・フィルムが粒間で連結を維持できないために、グラファイトによっては下部地殻の低比抵抗が説明できないことが実験で示された。伝導性鉱物の配列による異方性の出現についての計算機実験も行った。

Research Products

• [Journal Article] A heating process of Kuchi-erabu-jima volcano, Japan, as inferred from geomagnetic field variations and electrical structure (2010)
  • Author(s): Kanda, W., M.Utsugi, Y.Tanaka, T.Hashimoto, I.Fujii, T.Hasenaka, N.Shigeno
  • Journal Title: J.Volcanol.Geotherm.Res. 189 Pages: 158-171
  • Peer Reviewed
• [Journal Article] Electrical conductivities of pyrolitic mantle and MORB materials up to the lower mantle conditions (2010)
  • Author(s): Ohta, K., K.Hirose, M.Ichiki, K.Shimizu, N.Sata, Y.Ohishi
  • Journal Title: Earth and Planetary Science Letters 289 Pages: 497-502
  • Peer Reviewed
• [Journal Article] Electrical conductivity measurements of periclase under high pressure and high temperature (2010)
  • Author(s): Wu, X.P., B.H.Zhang, J.S.Xu, T.Katsura, S.M.Zhai, T.Yoshino, G.Manthilake, A.Shatzkiy
  • Journal Title: Physica B 405 Pages: 53-56
  • Peer Reviewed
• [Journal Article] Audio-frequency magnetotelluric imaging of the Hijima fault in the Yamasaki fault system, southwest Japan (2010)
  • Author(s): Yamaguchi, S., Y.Ogawa, K.Fuji-ta, N.Ujihara, H.Inokuchi, N.Oshiman
  • Journal Title: Earth Planets Space (IN PRESS)
  • Peer Reviewed
• [Journal Article] Electrical conductivity of mantle peridotite at the uppermost lower mantle condition (2010)
  • Author(s): Yoshino, T., D.Yamazaki, E.Ito, T.Katsura
  • Journal Title: Journal of Physics : Conference Series (In press)
  • Peer Reviewed
• [Journal Article] Structural controls on the 1998 volcanic unrest at Iwate Volcano : relationship between shallow electric resistive body and possible magmatic fluid ascent route (2009)
  • Author(s): Aizawa, K., Y.Ogawa, M.Mishina, K, Takahashi, S.Nagaoka, N.Takagi, S.Sakanaka, T.Miura
  • Journal Title: J.Volcanol.Geotherm.Res. 187 Pages: 131-139
  • Peer Reviewed
• [Journal Article] A model for observed circular polarized electric fields coincident with the passage of large seismic waves (2009)
  • Author(s): Honkura, Y., Y.Ogawa, M.Matsushima, S.Nagaoka, N.Ujihara, T.Yamawaki
  • Journal Title: J.Geophys.Res. 114 Pages: B10103
  • Peer Reviewed
• [Journal Article] An overview of electrical conductivity structures of the crust and upper mantle beneath the northwestern Pacific, the Japanese Islands, and continental East Asia (2009)
  • Author(s): Ichiki, M., K.Baba, H.Toh, K.Fuji-ta
  • Journal Title: Gondwana Research 16 Pages: 545-562
  • Peer Reviewed
• [Journal Article] A magnetotelluric study of Mount Ruapehu volcano, New Zealand (2009)
  • Author(s): Ingham, M.R., H.M.Bibby, W, Heise, K.A.Jones, P.Cairns, S.Dravitzki, S.L.Bennie, T.G.Caldwell, Y.Ogawa
  • Journal Title: Geophys.J.Int. 179 Pages: 887-904
  • Peer Reviewed
• [Journal Article] P-V-T relations of wadsleyite determined by in situ X-ray diffraction in a large-volume high-pressure apparatus (2009)
  • Author(s): Katsura, T., A.Shatskiy, M.A.G.M.Manthilake, S.Zhai, D.Yamazaki, T.Matsuzaki, T.Yoshino, A.Yoneda, E.Ito, M.Sugita, N.Tomioka, A.Nozawa, K.Funakoshi
  • Journal Title: Geophysical Research Letters Pages: L11307
  • Peer Reviewed
• [Journal Article] Electrical conductivity of the major upper mantle minerals, a review (2009)
  • Author(s): Katsura, T., T.Yoshino, T.Matsuzaki, G.Mathilake
  • Journal Title: Russian Geology and Geophysics 50 Pages: 1139-1145
  • Peer Reviewed
• [Journal Article] Electrical conductivity of wadsleyite as a function of temperature and water content (2009)
  • Author(s): Manthilake, G., T.Matsuzaki, T.Yoshino, S.Yamashita, E.Ito, T.Katsura
  • Journal Title: Physic of Earth and Planetary Interiors 174 Pages: 10-18
  • Peer Reviewed
• [Journal Article] Apparent Magnetization intensity map on Sakurajima volcano, Kyushu, Japan, inferred from low-altitude, high-density helicopter-borne aeromagnetic surveys (2009)
  • Author(s): Okubo A., W.Kanda, Y.Tanaka, K.Ishihara, D.Miki, M.Utsugi, T.Takayama, M.Fukusima
  • Journal Title: Tectonophysics 478 Pages: 34-42
  • Peer Reviewed
• [Journal Article] Three-dimensional geomagnetic response functions for global and semi-global scale induction problems (2009)
  • Author(s): Shimizu, H., T.Koyama, K.Baba, H.Utada
  • Journal Title: Geophys.J.Int. 178 Pages: 123-144
  • Peer Reviewed
• [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., T.Koyama, M.Obayashi, Y.Fukao
  • Journal Title: Earth Planet Sci.Lett. 281 Pages: 249-257
  • Peer Reviewed
• [Journal Article] The fluid and deformation regime of an advancing subduction system ; Marlborough, New Zealand (2009)
  • Author(s): Wannamaker, P.E., T.G.Caldwell, G.R.Jiracek, V.Maris, G.J.Hill, Y.Ogawa, H.M.Bibby, S.B.Bennie, W.Heise
  • Journal Title: Nature 460 Pages: 733-U90
  • Peer Reviewed
• [Journal Article] Modification of the Network-MT method and its first application in imaging the deep conductivity structure beneath the Kii Peninsula, southwestern Japan (2009)
  • Author(s): Yamaguchi, S., Uyeshima, M., Murakami, H., Sutoh, S., Tanigawa, D, Ogawa, T., Oshiman, N., Yoshimura, R., Aizawa, K., Shiozaki, I., Kasaya, T.
  • Journal Title: Earth Planets Space 61 Pages: 957-971
  • Peer Reviewed
• [Journal Article] Texture of (Mg,Fe)SiO3 perovskite and ferro-periclase aggregate : implications for rheology of the lower mantle (2009)
  • Author(s): Yamazaki, D., T.Yoshino, T.Matsuzaki, T.Katsura, A.Yoneda
  • Journal Title: Physics of Earth and Planetary Interiors 174 Pages: 13-144
  • Peer Reviewed
• [Journal Article] Magnetotelluric Transect of the Niigata-Kobe Tectonic Zone, Central Japan : A Clear Correlation between Strain Accumulation and Resistivity Structure (2009)
  • Author(s): Yoshimura, R., N.Oshiman, M.Uyeshima, H.Toh, T.Uto, H.Kanezaki, Y.Mochido, K.Aizawa, Y.Ogawa, T.Nishitani, S.Sakanaka, M.Mishina, H.Satoh, T.Goto, T.Kasaya, S.Yamaguchi, H.Murakami, T.Mogi, Y.Yamaya, M.Harada, I.Shiozaki, Y.Honkura, S.Koyama, S.Nakao, Y.Wada, Y.Fujita
  • Journal Title: Geophys.Res.Lett. 36 Pages: L200311
  • Peer Reviewed
• [Journal Article] Well-wetted olivine grain boundaries in partial molten peridotites in the asthenosphere (2009)
  • Author(s): Yoshino, T., D.Yamazaki, K.Mibe
  • Journal Title: Earth and Planetary Science Letters 283 Pages: 167-173
  • Peer Reviewed
• [Journal Article] Laboratory electrical conductivity measurement of mantle minerals (2009)
  • Author(s): Yoshino, T.
  • Journal Title: Survey in Geophysics 31 Pages: 163-206
  • Peer Reviewed
• [Journal Article] The effect of water on the electrical conductivity of olivine aggregates and its implications for the electrical structure in the upper mantle (2009)
  • Author(s): Yoshino, T., T.Matsuzaki, A.Shatzkiy, T.Katsura
  • Journal Title: Earth and Planetary Science Letters 288 Pages: 291-300
  • Peer Reviewed
• [Journal Article] Reply to Comments on "Electrical conductivity of wadsleyite as a function of temperature and water content" by Manthilake et al. (2009)
  • Author(s): Yoshino, T., T.Katsura
  • Journal Title: Physics of Earth and Planetary Interiors 174 Pages: 22-23
  • Peer Reviewed
• [Journal Article] Effect of iron content on electrical conductivity of ringwoodite, with implications for electrical structure in the mantle transition zone (2009)
  • Author(s): Yoshino, T., T.Katsura
  • Journal Title: Physic of Earth and Planetary Interiors 17 Pages: 3-9
  • Peer Reviewed
• [Journal Article] 上部マントル主要構成 鉱物の電気伝導度 (2009)
  • Author(s): 桂智男、芳野極、松崎琢也、ギートマンティラケ
  • Journal Title: 鉱物科学会誌 38 Pages: 33-38
  • Peer Reviewed
• [Journal Article] MT法による電気伝導度構造研究の現状 (2009)
  • Author(s): 上嶋誠
  • Journal Title: 地震 第2輯 61 Pages: S225-S238
  • Peer Reviewed
• [Presentation] 鬼首カルデラの3次元比抵抗構造 (2010)
  • Author(s): 小川康雄・吹野浩美・市來雅啓
  • Organizer: シンポジウム「地殻流体活動としてみた松代群発地震」
  • Place of Presentation: 産総研 つくば
  • Year and Date: 2010-03-26
• [Presentation] 岩手・宮城内陸地震域の浅部2次元比抵抗構造 (2010)
  • Author(s): 坂中伸也・市原寛・三品正明・西谷忠師・上嶋誠・茂木透・小川康雄・山谷祐介・網田和宏・三浦卓也・篠原弘志
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-17
• [Presentation] 蔵王周辺の比抵抗構造と地震活動 (2010)
  • Author(s): 前原祐樹・小川康雄・吹野浩美・長竹宏之
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-17
• [Presentation] 地殻流体の電磁イメージング班プロジェクト紹介「地殻流体:その実態と沈み込み変動への役割」 (2010)
  • Author(s): 小川康雄
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-17
• [Presentation] Modeling ocean bottom MT data at Marmara Sea, Turkey (2010)
  • Author(s): T.Kaya, Y.Ogawa, T.Kasaya, S.B.Tank, M.K.Tuncer, N.Oshiman, Y.Honkura, M.Matsushima
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-17
• [Presentation] VOLCANO LOOPの理論計算 (2010)
  • Author(s): 長竹宏之・小川康雄・神田径
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] 姶良カルデラおよび周辺における電磁気構造調査(序報) (2010)
  • Author(s): 神田径・小川康雄・笠谷貴史・市原寛・八木原寛・橋本武志・小山崇夫・Bulent Tank・Tulay Kaya・宇津木充・井上寛之・園田忠臣
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] 鬼首カルデラの広帯域MT観測(序報) (2010)
  • Author(s): 吹野浩美・小川康雄・市來雅啓・長竹宏之
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] 草津白根火山ボーリングコアの粘土鉱物の分析 (2010)
  • Author(s): 横山達也・野上健治・小川康雄
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] 地震ダイナモ効果の観測 (2010)
  • Author(s): 栗城麻由・本蔵義守・松島政貴・小川康雄
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] 3D magnetotelluric Modeling around the Nagamachi-Rifu fault (2010)
  • Author(s): S.B.Tank・Y.Ogawa・M.Mishina・Y.Honkura
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] Role of crustal conductors at fault dynamics. A Case study : Armutlu Peninsula, Turkey (2010)
  • Author(s): S.B.Tank, Y.Ogawa, Y.Honkura, M.K.Tuncer, N.Oshiman・M.Matsushima・T.Kaya・E.Tolak
  • Organizer: CA研究会
  • Place of Presentation: 東大地震研
  • Year and Date: 2010-02-16
• [Presentation] IMAGING OF A VAPOR RESERVOIR AT KUSATSU-SHIRANE VOLCANO, JAPAN, BY THREE-DIMENSIONAL MT INVERSION AND MICROEARTHQUAKES (2009)
  • Author(s): Nurhasan, YASUO OGAWA, S.Bulent Tank, Naoto Ujihara, Yoshimori Honkura, Teruo Yamawaki
  • Organizer: 11th IAGA General assembly
  • Place of Presentation: Sopron, Hungary
  • Year and Date: 20090823-20090830
• [Presentation] ELECTRIC FIELD VARIATIONS GENERATED BY GROUND MOTION AND THEIR APPLICATION TO GROUNDWATER RESEARCH (2009)
  • Author(s): Y.HONKURA, M.Matsushima, Y.Ogawa
  • Organizer: 11th IAGA General assembly
  • Place of Presentation: Sopron, Hungary
  • Year and Date: 20090823-20090830
• [Presentation] Imaging of a vapor reservoir at Kusatsu-Shirane volcano, by 3D-MT inversion (2009)
  • Author(s): 小川康雄, ヌルハッサン, タンクブレント, 氏原直人, 本蔵義守, 山脇輝夫
  • Organizer: 地球電磁気地球惑星圏学会
  • Place of Presentation: 金沢大学、石川
  • Year and Date: 2009-09-27
• [Book] 地球内部の電気伝導度構造, 地球電磁気・地球惑星圏学会学校教育WG編, 「太陽地球系科学」 (2010)
  • Author(s): 藤浩明
  • Total Pages: 第11章分担執筆
  • Publisher: 京都大学出版会(印刷中)