Electromagnetic response to deformation of gouge bearing rock and SP observation using universal line

• Project/Area Number: 26560186
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Osaka City University
• Principal Investigator: Nakagawa Koichi 大阪市立大学, 都市研究プラザ, 都市研究プラザ特別研究員 (80047282)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2016: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: ガウジ / 地すべり / 岩盤破壊 / 自然電位 / 活断層 / 震源過程 / 地震予知 / せん断分極（SIP) / 破壊予知 / SIP / せん断分極

Outline of Final Research Achievements

From previous studies, SIP ( Shear Induced Polarization) phenomenon associated with deformation of the gouge sample emerged. An observation of spontaneous potential was conducted at landslide area in Ozu City, Ehime Pref. in order to examine the phenomenon of SIP in the real field. Thirteen carbon rod electrodes were buried in the ground along to landslide slip axis, in space of 5 meters. Also, the quantities of precipitation, temperature and soil moisture content were measured simultaneously. During four months up to present, rapid changes of spontaneous potential induced with possible landslide were observed by three times of strong rain more than 10mm/hour.

Research Products

• [Presentation] A case study of soil type identification for levee structure by electric survey with unified cone field test (2015)
  • Author(s): M. Mimura, Y. Iwasaki, K. Nakagawa, A. Jomori, M. Yoshimura, M. Fujiwara and M. Uno
  • Organizer: 12th SEGJ International Symposium
  • Place of Presentation: Intnl. Res. C.(Ito Hall, Bunkyou-ku, Tokyo)
  • Year and Date: 2015-11-18
  • Int'l Joint Research
• [Presentation] Resistivity profiles and foundation structure of Central Tower in Bayon Temple, Angkor Thom (2015)
  • Author(s): K. NAKAGAWA, Y. IWASAKI, M. ARAYA, S. YAMADA,, I. SHIMODA, T. NAKAGAWA and T. KOYAMA
  • Organizer: International association of Engineering Geology
  • Place of Presentation: Kyoto Univ., DPRI,(Uji City, Kyoto Pref.)
  • Year and Date: 2015-09-26
  • Int'l Joint Research
• [Presentation] ガウジを挟在するすべり破壊に伴う電位分布特性 (2015)
  • Author(s): 中川康一
  • Organizer: 日本応用地質学会
  • Place of Presentation: 京都大学防災研究所(京都府宇治市五ヶ庄）
  • Year and Date: 2015-09-24 – 2015-09-25
• [Presentation] ガウジを挟在するすべり破壊に伴う電位分布特性 (2015)
  • Author(s): 中川康一
  • Organizer: 日本応用地質学会
  • Place of Presentation: 京都大学防災研究所(京都府宇治市)
  • Year and Date: 2015-09-24
• [Presentation] 河川堤防の電気探査と地盤特性(2) (2015)
  • Author(s): 三村衛，岩崎好規，中川康一，城森明, 吉村貢，藤原照幸，宇野匡範
  • Organizer: 物理探査学会
  • Place of Presentation: 石川県文教会館(石川県金沢市)
  • Year and Date: 2015-09-24
• [Presentation] バイヨン寺院(アンコールトム)直下の比抵抗断面と地下構造 (2015)
  • Author(s): 中川康一・岩崎好規・新谷眞人・山田俊亮・下田一太・中川武・小山倫史
  • Organizer: 日本応用地質学会関西支部
  • Place of Presentation: 大阪市立大学文化交流センター(大阪府大阪市)
  • Year and Date: 2015-05-26
• [Presentation] SIP(Shear-induced Polarization,せん断分極)のメカニズムについて (2014)
  • Author(s): 中川康一
  • Organizer: 日本応用地質学会関西支部
  • Place of Presentation: 大阪市立大学文化交流センター(大阪府大阪市北区梅田）
  • Year and Date: 2014-06-19