Technical Report of the Kakioka Magnetic Observatory Vol.13 No.01,02， p.7， 2016,Feb
Study of long term stability of geoelectric obserbation by a short base line
Kenji MORINAGA & Takeshi TOYA
Abstract
Instability generated by fluctuations of the contact potential difference by the precipitation is an unsolved problem in a geoelectric field observation at Kakioka magnetic observatory. To investigate the fluctuation by a precipitation and the long term stability of the observation data, we carried out the multi-electrodes observation using a number of copperplate electrodes and equilibrium electrodes.
On the basis of examinations, we obtained the following conclusions.
? A equilibrium electrode is unfitted for a long-term geoelectric field observation.
? The influence of a precipitation is related to the difference in the thicknesses of the loam layer between the pair of electrodes.
? When the temperature between the pair of electrodes is different, there is a possibility that the fluctuation of the data is proportional to the temperature difference.
