Observations of changes in the geomagnetic field by a proton precession magnetometer and a second-order G.S.I. magnetometer were carried out at stations in the Matsushiro earthquake area where we had an earthquake swarm in 1965. Two series of magnetic survey as well as an earth-current observation were also conducted there. A strong magnetic anomaly associated with a volcanic dome called Mt. Minakamiyama was found. Comparisons between the results of magnetic observation there and those at the Kanozan Geodetic Observatory and the Oshima Magnetic Observatory seem to suggest occurrences of local anomalous changes in the geomagnetic field of the order of 10γ that might be associated with seismic activities although elimination of general magnetic changes such as magnetic storm, daily variation and the like was not quite complete. An anomalous change in earth-currents was also observed at the time of a relatively large earthquake.
1965年8月に始つた松代地震群に伴なうと思われる地磁気・地電流変動の観測が行なわれた.同年10～12月の期間における観測およびその結果の概略を以下に述べる. 1. 観測の概要 1-1.プロトン磁力計による観測
雑誌名
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo
巻
44
号
1
ページ
363 - 408
発行年
1966-07-25
ISSN
00408972
書誌レコードID
AN00162258
フォーマット
application/pdf
日本十進分類法
453
出版者
東京大学地震研究所
出版者別名
Earthquake Research Institute, University of Tokyo
Geomagnetic and Geoelectric Studies of the Matsushiro Earthquake Swarm (1)
ji0441021.pdf
(2.08MB)
