Research on seismicity characteristics and regional stress field in fujian area

Through the background analysis of geological tectonic and seismicity in Fujian area,combining with the seismicity(ML≥4.0) in Fujian area during 2007~2009,the seismicity enhanced remarkably,it also shows that the level of seismicity will be promoted in southeastern coastal areas.Analysis the result obtained from focal mechanism solution of seven earthquakes(ML≥4.0),in Gutian reservoir area is dipslip normal fault,while others are strike-slip faults.The direction of 7 compressive principal stress axes are different.The results of composite plane solution in divided zones obtained from moderate intensity seismicity in Fujian area shows that the direction of regional stress field is NW,while,the direction is different in different areas,such as,in central and north of Fujian coastal region the direction is NW,in central and north of Fujian inland area the direction is NNW and in south of Fujian coastal region the direction is EW,which may caused by the shove of Philippine plate from east to west.