This paper is a brief preliminary report of earth-current observed at Kakioka and Toyohara from Aug. 1932 to Aug. 1933, the 2nd polaryear. Comparing records at both places, we have found a striking similarity in spite of their geographical and geological differences. The diurnal variation curve has two maxima at 4
h a. m. and 2
h p. m., and at Kakioka, the east-and north-components have mean ranges of 0.78 and 0.50 millivolts per 100
m respectively, while at Toyohara, 0.73 and 0.29 millivolts. It is interesting that the general direction of diurnal variation is SW-NE, approximately directing to the magnetic northpole as at some other places in the world. We try to explain a pretty large variation in earth-current accompanied by thunderstorm or shower, but earth-magnetism does not so large variations. By a simple calculation, it was found that this current does not flow deeper than 800
m beneath the earth surface, supposing a mean resistivity of the soil is 10
4 ohms per cm.
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