Memoirs of the Kakioka Magnetic Observatory Supplement No.02， p.1, March, 1966

The Anomaly of Geomagnetic Variation in Japan(Part 1)

Kuboki, T. & Osima, H.

Abstract

 Many investigators have already made an attempt to deduce the subterranean electric conductivity by using of geomagnetic short period (several or several tens minutes) variations. T. Rikitake and his co-workers have made many investigations on the great geomagnetic anomaly in the vicinity of Japan lslands.
  The vectors of geomagnetic variation are always restricted on a certain specific plane, which is represented by a vector S, for each station. In this paper, the authors studied the characters of the vector S for the geomagnetic variations of the periods from 10 sec to several hours for several stations in Japan. As the results, it was found that the topographic distribution is unexpectedly complicated, for example, the absolute values of vector S corresponding to the geomagnetic variation ssc or pi2 become anomalously large at some stations, which seems to be frequent at stations close to sea coast, and that the vector S of pc3 seems to tend towards the direction of the maximum dip of the Mohorovicic discontinuous surface under the station, and that the principal direction of earth current is perpendicular to the vector S at stations of Kakioka, Memambetsu and Kanoya.

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