抄録
Geoelectrical fluctuations are the end product of several geophysical phenomena. In particular geoelectrical signals measured in seismically active areas can be attributed to stress and strain changes, associated with earthquakes. In order to study the geoelectrical potential difference changes associated with the earth's crustal activities, it is important to discriminate from other noises because they are generally weak. The complexity of this problem has suggested the development of advanced statistical methods to investigate the heterogeneous nature of these fluctuations. In this paper we analyzed the time dynamics of short-term variability of geoelectrical field measured at Kiyosumi station, located in southern part of Boso peninsula, Japan. We tried to apply principal component analysis (PCA) and singular spectral analysis (SSA) to detect and reduce precipitation effects which are the most intense noise in geoelectrical potential difference data. The results show an application of PCA to two orthogonal electric data can detect the precipitation and SSA has a potential to remove the precipitation effects.
