The Anomaly of Geomagnetic Variation in Japan(Part 2)
Kuboki, Y. & Osima, H.
Abstract
In a previous paper (Part 1), the behaviour of the vector of geomagnetic variations in the vicinity of Japan Island was generally discussed. Then, in this paper, problems of small area in the Kanto District are considered with the data of high density survey of ″The special observations for the electrification-plan of the Joban railway ". As a result of this study, a local geomagnetic anomaly is found in the central area of the Kanto District. The relations between this anomaly, many epicenters distributed in this district and the subterranean electrical construction are studied. There is the high conductive layer from 30km to about 100km depth in this district. Then, the authors speculate that the Kanto anomaly is caused by the mere local anomalous construction that the low conductive layer of the deeper level sticks out to about 40-60km depth and high conductive layer pushes up to about several kilometer depth at very small area in the middle eastern parts of the Kanto district.
In the present stage, simple relations between the distribution or the frequency characteristic of the anomaly and others such as gravity, moho layer geology etc. are not found, but in future if the observing points are densely distributed, the explanations for these questions may be expected.
