| Project/Area Number |
11555268
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
資源開発工学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
MOGI Toru Hokkaido Univ., Grad. School of Sci., Asso. Prof., 大学院・理学研究科, 助教授 (80182161)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIDA Toshihiro Advanced Industrial Sci. & Tech., Group Leader, 知圏資源環境部門, 研究グループ長
SHIMOIZUMI Masashi Kyushu Colledge of Polytechnics, Asso. Prof., 助教授
TANAKA Yoshikazu Kyoto Univ., Grad. School of Sci., Prof., 大学院・理学研究科, 教授 (00025420)
TOSHIOKA Tetsuma OYO Co. Ltd., Research Group Leader, つくば技術開発センター, 研究グループ長
EHARA Sachio Kyushu Uniy., Grad.School of Eng., Prof., 大学院・工学研究院, 教授 (10002346)
福岡 晃一郎 応用地質株式会社, 研究員
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥8,100,000 (Direct Cost: ¥8,100,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥4,100,000 (Direct Cost: ¥4,100,000)
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| Keywords | EM Survey / 3D modeling / 3D inversion / 電磁気探査 / 地殻構造探査 / 地質構造探査 |
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| Research Abstract |
The purpose of this study was constructing an appropriate survey system to image three dimensional (3D) subsurface resisitivity structure using the magnetotelluric (MT) method.
We developed the data processing scheme involving the robust stacking method based on the "M parameter" estimation, the impedance estimation method using Singular Value Decomposition of the data matrix and impedance smoothing method based on the Hirbert transformation between phase and impedance. We have verified the effectiveness of these techniques.
We also developed a high accuracy 3D EM modeling scheme based on the staggered grid finite difference method. We tried to improve the condition of a large size coefficient matrix to easily solve and have overcome the problem of high resistivity contrast model and topography model in this scheme. The 3D inversion scheme based on the ABIC constrained smoothness least square method was modifying to apply a actual field data.
We carried out MT survey at 25 sites distributed like a grid in the Nakatonbetsu area, Northern Hokkaido as a demonstrative research for the survey system developed in this research. We used MTU5 wide band MT survey machine and obtained electric and magnetic field data at 40 frequencies in the range of 380-0.00055 Hz. To obtain lower frequency data, we carried out MT observation using the fluxgate type magnetometer over two months. A reasonable 3D resistivity structure was imaged but the result suggested that we need further study to improve the resolution at deeper part
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