Geoelectric potential differences and geomagnetic data observed at Southern Kanto area, Japan

Summary form only given. In order to investigate the relationship between electromagnetic phenomena and crustal activity, sophisticated geoelectric potential difference and geomagnetic field measurements have been realized since February, 2000. The frequency range is ULF (f<1 Hz). The ULF geomagnetic anomalous changes associated with the crustal activity have been reported based on polarization analysis, which is the spectral density ratio between horizontal and vertical components, using principle component analysis. We observe both 3 magnetic and 2 electric components on the ground simultaneously. In this talk, the electromagnetic environment near the station is investigated over a long period of time. The relationship between polarization and regional seismicity shows that there seems to be a threshold of seismic energy at the site and it is concerned with enhancement of polarization. We remark on the behavior of the orientation on various frequency bands. Further, we calculated the variation of transfer functions, and the variation of MT impedance.