By analyzing the seismic mechanism of the Tangshan earthquake and its pattern of movement through the study of ground deformation and ground strain of the Tangshan earthquake area it is clear that the breeding and occurrence of this event are controlled by a long-term intense active fault zone. By the ground deformation, displacement, tectonic features and seismic effects after the event, this causative fault is known to be composed of a group of NNE trending right turn strike-slip faults and thus we call it the Tangshan active fault zone
