| Project/Area Number |
12558041
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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 |
Natural disaster science
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SASATANI Tsutomu Hokkaido Univ., Grad. School of Sci., Asso. Prof., 大学院・理学研究科, 助教授 (10002148)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAI Nobuo Hokkaido Univ., Grad. School of Eng., Lec., 大学院・理学研究科, 助手 (10281792)
KAGAMI Hiroshi Hokkaido Univ., Grad. School of Eng., Prof., 大学院・理学研究科, 教授 (70016476)
KASAHARA Minoru Hokkaido Univ., Grad. School of Sci., Prof., 大学院・理学研究科, 教授 (40001846)
ANDO Fumihiko Katsujima Co. Ltd., 技術部長(研究職)
HAYAKAWA Fukutoshi Ueyama Shisui Kogyo Co. Ltd., 開発部長(研究職)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | Borehole seismometer / Sapporo urban districts / Seismic response / Urban seismicity / Blind fault / 水井戸 / ボアホール地震観測 / 光ファイバーケーブル / 微小地震観測 / 地震波増幅特性 / 地震動の空間変動 |
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| Research Abstract |
We have developed a simple method for installing a deep borehole seismometer inside a preexisting well. The developed points are (1)double-casing system down to the well-bottom to protect effects due to well-water movement, (2)boring at the bottom of the preexisting well to install the borehole seismometer, (3)damping system to protect vibration noises propagating the inner casing, and (4)use of an optical fiber cable to transmit the digital data. Our system is easy to install and take up the borehole seismometer.
We have confirmed our system comparing the seismograms with those by the other borehole seismometers. Micro-earthquake activity beneath Sapporo urban districts has been studied based on data from several borehole seismometers. The epicentral distribution shows a linear trend with the NW-SE direction ; this might represent a blind fault beneath Sapporo urban districts. Finally we have studied the seismic response of sedimentary layers based on surface and borehole seismic data.
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