SECULAR CHANGE OF THE GEOMAGNETIC TOTAL INTENSITY AT TOTTORI, JAPAN (II)

Abstract

Secular change of the geomagnetic total intensity at Tottori with respect to Kakioka magneticobservatory from 1967 to 1977 is analyzed by using the data of a proton precession magnetometerobservation. The general trend of secular change changed from decreasing to increasing in 1974.But this trend is compatible with those observed in the whole area of Japan.Properties of the various fluctuations included in the general trend of secular change arestudied in details to evaluate an accuracy of detection of anomalous changes. It is concludedthat an overall accuracy of the monthly mean difference between two stations is about one gamma.Secular change of the geomagnetic total intensity at Tottori with respect to Kakioka magneticobservatory from 1967 to 1977 is analyzed by using the data of a proton precession magnetometerobservation. The general trend of secular change changed from decreasing to increasing in 1974.But this trend is compatible with those observed in the whole area of Japan.Properties of the various fluctuations included in the general trend of secular change arestudied in details to evaluate an accuracy of detection of anomalous changes. It is concludedthat an overall accuracy of the monthly mean difference between two stations is about one gamma