NEAR EARTH SURFACE ANOMALIES OF THE ATMOSPHERIC ELECTRIC FIELD AND EARTHQUAKES
HAO JIANGUO(Institute of Geophysics, State Seismological Bureau)
A few years' continuous observation and investigation have been made of the static electric field in the atmosphere near ground surface at the Baijiatuan Seismic Station using different instruments since 1977. A relatively good correlation has been found between negative anomalies of the atmospheric electric potential gradient and local earthquakes through analysis and comparison. In other words, a relatively large negative anomaly of the electric field was recorded almost for each local quake of either ML≥4.0 with epicentral distance within 100 km or ML≥5.0 with epicentral distance within 250km, while no such anomaly appeared during earthquake-quiet periods. After the few years' observation and investigation we feel that it is possible to reveal a reliable precursor of earthquake through further study of the atmospheric static electric field.