EM Imaging beneath the Back-Arc Region of Southwest Japan

2009 Fiscal Year Final Research Report

• Project/Area Number: 19340127
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: OSHIMAN Naoto Kyoto University, 防災研究所, 教授 (70185255)
• Co-Investigator(Kenkyū-buntansha): YOSHIMURA Ryokei 京都大学, 防災研究所, 助教 (50346061)
• Co-Investigator(Renkei-kenkyūsha): TOH Hiroaki 京都大学, 理学研究科, 准教授 (40207519) ; SHIOZAKI Ichiro 鳥取大学, 工学部, 准教授 (80221290) ; KASAYA Takafumi 海洋研究開発機構, 地球内部ダイナミクス領域, 技術研究副主任 (90373456) ; YAMAZAKI Akira 気象庁, 気象研究所, 主任研究官 (70354529) ; FUJII Ikuko 気象庁, 気象研究所, 主任研究官 (90450303)
• Research Collaborator: SHIMOIZUMI Masashi 九州職業能力開発大学校, 教授 ; MURAKAMI Hideki 高知大学, 理学部, 准教授 ; YAMAGUCHI Satoru 神戸大学, 理学部, 講師 ; UYESHIMA Makoto 東京大学, 地震研究所, 准教授 ; SHINGAI Masafumi 九州職業能力開発大学校, 准教授
• Project Period (FY): 2007 – 2009
• Keywords: 海洋探査 / 地震 / 山陰地域 / 地球電磁気学 / 地殻・マントル構造 / 下部地殻 / 比抵抗構造 / 電気伝導度構造

Research Abstract

In order to investigate deeper resistivity structure and clarify the relationship between subducting Philippine Sea plate and the deeper resistivity structure beneath the San-in region, we carried out not only seafloor EM measurements in the Sea of Japan but also longer period MT surveys on land, along two N-S profiles passing through lines of longitudes, 134.3E and 133.4E. In land area, resistive upper crust and conductive lower crust are found. On the other hand, very conductive region is found in deeper part beneath the Sea of Japan, suggesting the existence of upwelling flow from deeper mantle.

Research Products

• [Journal Article] A small ocean bottom electromagnetometer and ocean bottom electorometer system with an arm-folding mechanism (2009)
  • Author(s): Takafumi Kasaya, Tadanori Goto
  • Journal Title: Exploration Geophysics 40(1) Pages: 41-48
  • Peer Reviewed
• [Journal Article] 西南日本背弧における導体地球の長周期応答 (2009)
  • Author(s): 南拓人・藤浩明・笠谷貴史・下泉政志・新貝雅文・大志万直人・吉村令慧・塩崎一郎・山崎明・藤井郁子・村上英記・山口覚・上嶋誠
  • Journal Title: CA論文集 Pages: 56-63
• [Journal Article] 海でのOBEM実験 (2008)
  • Author(s): 姫野康一郎・安松潤二・新貝雅文・佐藤数美・下泉政志・大志万直人・上嶋誠
  • Journal Title: 2008年CA研究会論文集 Pages: 20-26
• [Presentation] 西南日本背弧域における地下比抵抗構造の多次元性 (2009)
  • Author(s): 南拓人・下泉政志・笠谷貴史・大志万直人・藤浩明
  • Organizer: 2009年地球電磁気・地球惑星圏学会第124回講演会
  • Place of Presentation: 金沢大学
  • Year and Date: 2009-09-28
• [Presentation] 山陰地方で取得された海域・陸域データを用いた山陰地方の比抵抗構造 (2009)
  • Author(s): 笠谷貴史・大志万直人・藤浩明・下泉政志・塩崎一郎・吉村令慧・藤井郁子・山口覚・村上英記・山崎明
  • Organizer: 2009年地球電磁気・地球惑星圏学会第124回講演会
  • Place of Presentation: 金沢大学
  • Year and Date: 2009-09-28
• [Presentation] EM Imaging beneath the Back-Arc Region of Southwest Japan: Cooperative Seafloor and Land Surface EM Observations (2009)
  • Author(s): Naoto Oshiman, Ryokei Yoshimura, Hiroaki Toh, Takafumi Kasaya, Masashi Shimoizumi, Ichiro Shiozaki, Masafumi Shingai, Ikuko Fujii, Satoru Yamaguchi, Hideki Murakami, Akira Yamazaki, Makoto Uyeshima
  • Organizer: IAGA
  • Place of Presentation: Sopron, Hungary
  • Year and Date: 2009-08-28
• [Presentation] 西南日本背弧での海域・陸域MT観測 (2009)
  • Author(s): 大志万直人・藤浩明・笠谷貴史・塩崎一郎・下泉政志・吉村令慧・藤井郁子・山崎明・村上英記・山口覚・上嶋誠
  • Organizer: 2009年連合大会
  • Place of Presentation: 幕張メッセ
  • Year and Date: 2009-05-20
• [Presentation] Electrical Structure beneath the Back-arc Region of Southwest Japan: Results from a Seafloor Magnetotelluric Array Study (2008)
  • Author(s): Hiroaki Toh, Takafumi Kasaya, Masashi Shimoizumi, Naoto Oshiman, Ryokei Yoshimura, Ichiro Shiozaki, Ikuko Fujii, Masafumi Shingai, Satoru Yamaguchi, Hideki Murakami, Akira Yamazaki, Makoto Uyeshima, Takuto Minami
  • Organizer: AGU 2008 Fall Meeting
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2008-12-19
• [Presentation] MT Measurements in the San-in Region, Japan, in Cooperation with Seafloor Electromagnetic Observations in the Sea of Japan (2008)
  • Author(s): Naoto Oshiman, Ryokei Yoshimura, Ichiro Shiozaki, Satoru Yamaguchi, Hideki Murakami, Ikuko Fujii, Akira Yamazaki, Hiroaki Toh, Takafumi Kasaya, Masashi Shimoizumi, Masahumi Shingai, Makoto Uyeshima
  • Organizer: AGU 2008 Fall Meeting
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2008-12-19
• [Presentation] 海域・陸域データを用いた山陰地方の比抵抗構造 (2008)
  • Author(s): 笠谷貴史、大志万直人、藤浩明、下泉政志、塩崎一郎、吉村令慧、藤井郁子、山口覚、村上英記、山崎明
  • Organizer: 2008年連合大会
  • Place of Presentation: 幕張メッセ
  • Year and Date: 2008-05-29