| Project/Area Number |
01460051
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体地球物理学
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| Research Institution | Tottori University |
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Principal Investigator |
MIYAKOSHI J. Fac. General Education, Professor, 教養部, 教授 (60032116)
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| Co-Investigator(Kenkyū-buntansha) |
SASAI Y. Earthq. Res. Inst. Univ. Tokyo, Assistant, 地震研究所, 助手 (20012924)
SHIOZAKI I. Fac. General Education, Lecturer, 教養部, 講師 (80221290)
NISHIDA R Fac. General Education, Professor, 教養部, 教授 (90027269)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1990: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1989: ¥3,900,000 (Direct Cost: ¥3,900,000)
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| Keywords | Weter Dam Lake / Water Level Change / Rock Magnetism / Piezomagnetism / Geomagnetic Field / Streaming Potential / Geoelectric Potential / Tectono-magnetism / ピエゾ磁気 / 地電流 / テクトノマグネティズム / 地震予知 |
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| Research Abstract |
Continuous measurement of the geomagnetic and geoelectric field were carried out on the shore and its vicinity of the Sugesawa-dam Lake. Lake Nichinanko. which is located in the western part of Tottori Pref.
Objectives of the measurement are (1) to detect the local geomagnetic field caused by the load of the lake water through the piezomagnetism and (2) to detect the local geoelectric field caused by the lake water pressure in the circumstance of the probable existence of the leakage of water from the bottom or surrounding of the lake through the streaming potential phenomenon.
Continuous measurement started in the August of 1989 and we are now planning to continue until the end of 1991.
After the continuous measurement of about one year on the shore of the lake. We found the local geomagnetic change is concordant with the change of the water level of the dam lake. Decrease of the geomagnetic total intensity occurs simultaneously with the increase of the water level.
Piezomagnetic coefficient thus obtained are -0.014. -0.013 and -0.065 (nT/m) at DM1. DM2 and DM3. respectively. And they are concordant with the values obtained by Davis and Stacy (1972). Abudullabekov et al (1979) and Brennan and Hastie (1979).
As for the relationship between the time variation of the geoelectric potential difference between electrodes and the change of the water level of the lake. the increase of the potential difference. EP (1-0) and EP (2-0) seems to have occured simultaneously with the increase of the water level of thlake. However, we cannot get conclusion at this moment because of the fairly long interruption of the observation in the year of 1990.
In addition to these, we succeeded to observe a precursory change of the geoelectric potential differences EP (1-2) and EP (2-0) preceding the earthquake of M=5.3 which occured at about 4 kilometers distance from Nichinanko Lake.
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