Measurement of Seismic Wave with Vertically Induced Earth Potential Difference

Abstract

The earth potential difference (EPD) has been observed continuously for monitoring an earthquake at the urban area. A new measuring method of EPD is proposed to reduce the unnecessary signals induced by artificial and natural earth current sources. On this method EPD is measured through two electrodes that are buried at vertically different positions. On the earthquakes of more than 1 of intensity scale we can clearly observe EPD signals. These P-wave arraival times agree exactly with ones obtained by meteorological agency seismograph. The obtained data show that electrical field of vertical direction is higher by one order than one of horizontal direction.