Study on the relationship between modulated earthquakes more than M4.0 and moderate strong earthquakes more than M5 in Sichuan Province

The seismic events from the seismic catalogue of Sichuan Province since 1972 are selected and analyzed.The statistical corresponding data between earthquakes more than M4.0 and earthquakes more than M5.0 are calculated.The statistical corresponding data include 41 groups among which 14 groups are linked to the moderate strong earthquakes.It means that the link between modulated earthquakes more than M4.0 and moderate strong earthquakes more than M5.0 in Sichuan Province is weak.But their distance link among earthquakes more than M5.0 seems to be strong.The average distance between every two earthquakes is 93.94 kilometers and the average interval is 17.5 months.