A study on the tectonic stress field and seismic activity in Tengchong and its adjacent areas
In this study,the FMSI method was used to invert the stress field for Tengchong and its adjacent areas in Yunnan Province.Furthermore,fault slip tendency and seismic activity were carried out.The results show that the source mechanisms of Tengchong and its adjacent areas aremainly strike-slip types,with the maximum stress axis σ1 along the NNE-SSW direction,the minimum principal stress axis σ3 along the NWW direction,and both the maximum and minimum principal stress axes are near horizontal.The strike range of faults with strong slip tendency in the study area is mainly 40°-80°,160°-200°,220°-260°,and 340°-360°.The dip angle of the fault is 50°-70°,which is consistent with the tectonic setting of the area.Combined with the fault distribution analysis in this area,it is concluded that the Dayingjiang fault,Longchuanjiang fault and Longling-Ruili fault near Tengchong volcanic area may have obvious seismic activity trends in the future.From 2000 to 2021,there were 7 moderate-strong earthquakes of magnitude 4.0 or above in this area,and there were more seismic activities in the study area before 2012,with most of the seismic events of magnitude 4.0 and above occurred around 2011.Two of the seven earthquakes occurred near the faults with strong slipping tendency.
Tengchong areainversion of stress fieldstress shape factorslipping trend analysisseismic activity
万方数据
维普
