Memoirs of the Kakioka Magnetic Observatory Vol.07 No.02， p.143, March, 1956
On the Inequalities of the Diurnal Variations and the Short Period Variaiotns of the Earth-Currents
The diurnal variations of the earth-currents at Toyohara, Memambetsu, Morioka, Haranomachi Owashi and Kanoya have been compared with that of Kakioka. It is shown that the simple relation (2) exist between the observed variations.
Using the constants in the relation, it is possible to ascertain whether or not the long time-variations of the effective earth-resistivities are there. The preliminary results show that the effective earth-resistivities at Kakioka and Haranomachi may vary in recent few years.
The relation between the short period variations (period 5m-30m) at Haranomachi and Kakioka is likely given by the same formula (2), and again the most probable relation which was obtained empirically, have been also shown. (formula (3)).