LUNAR PHASE EFFECT ON EARTHQUAKE FREQUENCY IN THE YANSHAN SEISMIC ZONE
Ding Jianhai Huang Xuexiang (Center for Analysis and Prediction, State Seismological Bureau)
This paper deals with the influence of the lunar phase on earthquake frequency in accordance well the data of frequency of earthquakes (ML≥1.0) in the Yanshan seismic zone from April 1966 to August 1983. It has been 'found that an obvious lunar phase effect exists. The statistics tell that the fluctuation of the earthqueke frequency is modulated by the lunar phase. Peak values of the fluctuation are around the first and the fifteenth day of the lunar month as well as the fist and the last quarter of the moon. In study of earthquake frequency variation, the effect of lunar phase could not be neglected.