A study of atmospheric influence from earthquake statistics

We analyze daily variation in earthquake (EQ) occurrence to try to find a correlation with atmospheric tide whose basic period is 24 h exactly. In selection of earthquake ensembles we use a specially developed index of seismic activity. In this way we present statistics of earthquakes in Kamchatka during the last 40 years, in Japan during the last 7 years and in California during the last 72 years, which shows a weak but recognizable effect. We explain it by tidal modulation of the earthquake instability process.