This paper introduces the basic parameters,focal mechanism solutions and earthquake sequence characteristics of the Kalpin M_S5.3 earthquake sequence of December 1,2013,and analyzed seismic activity before the earthqu...This paper introduces the basic parameters,focal mechanism solutions and earthquake sequence characteristics of the Kalpin M_S5.3 earthquake sequence of December 1,2013,and analyzed seismic activity before the earthquake,the adjacent tectonic features and the precursory anomaly at fixed points within a range of 200 km. Research indicates:(1) The earthquake occurred on Kalpin fault,the source rupture type is thrust faulting with sinistral strike-slip component.( 2) The earthquake sequence is mainshock-aftershock type,with the aftershock distribution attenuating quickly and trending NE.(3) Abnormal seismic activity before the earthquake was characterized by seismically nesting quiescence of MS2. 0-4. 0 earthquakes,seismic quiescence of MS4. 0 earthquakes and seismic belts of MS3. 0 earthquakes in the Kalpin block, abnormal enhancement zone of moderate earthquakes on Puchang fault and seismological parameters.(4) Anomalies of precursory observation data at fixed stations are mainly characterized by mutation. Apart from the borehole tiltmeter in Halajun, the spatial distribution of other abnormal precursors showed a phenomenon of migration from the near field to far field and from the epicenter to the peripheries.展开更多
Taking the 2013 Tongliao MS5. 3 earthquake as a research subject, on the basis of statistical analysis of earthquake sequence using the HypoDD location method and focal mechanism solutions,the paper analyzes and discu...Taking the 2013 Tongliao MS5. 3 earthquake as a research subject, on the basis of statistical analysis of earthquake sequence using the HypoDD location method and focal mechanism solutions,the paper analyzes and discusses the relationship between the ML4. 4 and MS5. 3 earthquakes. The results show that the Tongliao MS5. 3 earthquake occurred under the background of medium-small earthquakes long-term quiescence and short-term enhancement in the epicentral area. The results of accurate seismic location shows that the Tongliao MS5. 3 earthquake sequence is distributed in the NW direction,extending 10 km,and the ML≥3. 0 aftershocks are concentrated south of the mainshock. The distance between the MS5. 3 mainshock and the ML4. 4 foreshock is about 1. 8 km,with a focal depth of 7. 208 km and 7. 089 km,respectively,their focal location is very close,and may have occurred on the same fault plane. The results of focal mechanism shows that the Tongliao MS5. 3 earthquake is of the strike-slip type,the focal mechanism of aftershocks are disordered,and with time lapse,the type is changed from strike-slip to thrust and normal faulting. The bigger foreshocks had similar focal mechanism and were all normal fault types,which exhibits to some extent,an obvious crustal medium anisotropy in the epicentral area before macroscopic rupturing,as represented by alignment fractures,with stress action enhanced,this"consistency"of seismic precursor regime would gestate the mainshock. According to the characteristics of temporal-spatial distribution of earthquake sequence and similarity of focal mechanism,we judge that the Tongliao MS5. 3 earthquake sequence is a foreshock-mainshock-aftershock type.展开更多
文摘This paper introduces the basic parameters,focal mechanism solutions and earthquake sequence characteristics of the Kalpin M_S5.3 earthquake sequence of December 1,2013,and analyzed seismic activity before the earthquake,the adjacent tectonic features and the precursory anomaly at fixed points within a range of 200 km. Research indicates:(1) The earthquake occurred on Kalpin fault,the source rupture type is thrust faulting with sinistral strike-slip component.( 2) The earthquake sequence is mainshock-aftershock type,with the aftershock distribution attenuating quickly and trending NE.(3) Abnormal seismic activity before the earthquake was characterized by seismically nesting quiescence of MS2. 0-4. 0 earthquakes,seismic quiescence of MS4. 0 earthquakes and seismic belts of MS3. 0 earthquakes in the Kalpin block, abnormal enhancement zone of moderate earthquakes on Puchang fault and seismological parameters.(4) Anomalies of precursory observation data at fixed stations are mainly characterized by mutation. Apart from the borehole tiltmeter in Halajun, the spatial distribution of other abnormal precursors showed a phenomenon of migration from the near field to far field and from the epicenter to the peripheries.
基金Science and Technology MajorProject of Inner Mongolia Autonomous Region,entitled“Research,development and promotion of earthquake prediction and early warning technology in key areas”.Seismic Regime Tracking Project of CEA,No.2018010124
文摘Taking the 2013 Tongliao MS5. 3 earthquake as a research subject, on the basis of statistical analysis of earthquake sequence using the HypoDD location method and focal mechanism solutions,the paper analyzes and discusses the relationship between the ML4. 4 and MS5. 3 earthquakes. The results show that the Tongliao MS5. 3 earthquake occurred under the background of medium-small earthquakes long-term quiescence and short-term enhancement in the epicentral area. The results of accurate seismic location shows that the Tongliao MS5. 3 earthquake sequence is distributed in the NW direction,extending 10 km,and the ML≥3. 0 aftershocks are concentrated south of the mainshock. The distance between the MS5. 3 mainshock and the ML4. 4 foreshock is about 1. 8 km,with a focal depth of 7. 208 km and 7. 089 km,respectively,their focal location is very close,and may have occurred on the same fault plane. The results of focal mechanism shows that the Tongliao MS5. 3 earthquake is of the strike-slip type,the focal mechanism of aftershocks are disordered,and with time lapse,the type is changed from strike-slip to thrust and normal faulting. The bigger foreshocks had similar focal mechanism and were all normal fault types,which exhibits to some extent,an obvious crustal medium anisotropy in the epicentral area before macroscopic rupturing,as represented by alignment fractures,with stress action enhanced,this"consistency"of seismic precursor regime would gestate the mainshock. According to the characteristics of temporal-spatial distribution of earthquake sequence and similarity of focal mechanism,we judge that the Tongliao MS5. 3 earthquake sequence is a foreshock-mainshock-aftershock type.
