This paper, first, analyzed the seismic activity patterns of the Datong-Yanggao earthquake sequence by 4 stages,finding that three times earthquakes of Mis were located in a same NNE seismically active zone and two ti...This paper, first, analyzed the seismic activity patterns of the Datong-Yanggao earthquake sequence by 4 stages,finding that three times earthquakes of Mis were located in a same NNE seismically active zone and two times located in 2 NWW seismically active zones. Then the focal-mechanism solutions of 12 earthquakes of M≥4 and 114 earthquakes of M≥1. 0 in various zones were obtained, a tectonic analysis was made for these data, the obtained fracture characteristic of this sequence is: the conjugate fracture combination with the NNE right lateral faults as its trunk and the two NWW left lateral faults as its branches. Finally, it is pointed out that there is an obvious difference between the seismic fracture and the tensile dip-slip tectonic activity of the main body of the seismic region.展开更多
In this paper,the basic conditions and characteristics of the Datong-Yanggao earthquake are described in detail.The type of the earthquake,the aftershock activity,the earthquake trend,the characteristics of damage are...In this paper,the basic conditions and characteristics of the Datong-Yanggao earthquake are described in detail.The type of the earthquake,the aftershock activity,the earthquake trend,the characteristics of damage are analyzed and discussed.This earthquake belongs to a sequence of earthquake swarm type and is of the concentratedly occurring characteristics of several main shocks in a time sequence,and the aftershock activity was normally attenuated.Because of the unreasonable design of buildings and repeated vibration by several destructive main shocks within a short period,the damage in the high intensity region was aggravated.The analysis and the prediction procedure of the 1991 Datong-Yanggao earthquake(Ms=5.8)are also briefly given.展开更多
文摘This paper, first, analyzed the seismic activity patterns of the Datong-Yanggao earthquake sequence by 4 stages,finding that three times earthquakes of Mis were located in a same NNE seismically active zone and two times located in 2 NWW seismically active zones. Then the focal-mechanism solutions of 12 earthquakes of M≥4 and 114 earthquakes of M≥1. 0 in various zones were obtained, a tectonic analysis was made for these data, the obtained fracture characteristic of this sequence is: the conjugate fracture combination with the NNE right lateral faults as its trunk and the two NWW left lateral faults as its branches. Finally, it is pointed out that there is an obvious difference between the seismic fracture and the tensile dip-slip tectonic activity of the main body of the seismic region.
文摘In this paper,the basic conditions and characteristics of the Datong-Yanggao earthquake are described in detail.The type of the earthquake,the aftershock activity,the earthquake trend,the characteristics of damage are analyzed and discussed.This earthquake belongs to a sequence of earthquake swarm type and is of the concentratedly occurring characteristics of several main shocks in a time sequence,and the aftershock activity was normally attenuated.Because of the unreasonable design of buildings and repeated vibration by several destructive main shocks within a short period,the damage in the high intensity region was aggravated.The analysis and the prediction procedure of the 1991 Datong-Yanggao earthquake(Ms=5.8)are also briefly given.
