Seismic electromagnetic field varietions in LF to MF frequency band has been observed as precursory phenomena of earthquake with cross loop antenna. This radio wave observation system described here that it carries out the observation with geoelectric signals observation system and attempts the accuracy improvement of discrimination of the geoelectric signals change and identification by the comparison of the data mutually. And, it also made that the direction of the electromagnetic wave radiated as precursory phenomenon of earthquake was known to be the purpose.
展开▼
