【摘要】 唐山7.8级地震后,随即在宁河地区发生一系列地震,称为宁河地震群。在宁河地震群中发现有七个地震的波形与该区一般地震波形不同,但它们彼此又极为相似。正是这七个波形相似的地震却具有明显的前震性质,在其后差不多时间里,几乎对应了宁河地区全部M_s≥5.5级中强地震。根据这些波形相似的前震,讨论了宁河地震主破裂面有可能是北西方向左旋节面。更多还原

【Abstract】 After the Tangshan earthquake(M_s=7.8, July 28, 1976) a series of earthquakes occured in the Ninghe region, it is called the Ninghe earthquake swarm. In the swarm waveforms of seven earthquakes whose are different from others in the region, but similar to each other. These earthquakes with similar waveforms are characterized significantly by the foreshock. Such ear thquakes are regularly followed by moderate-strong earthquakes with Ms≥5.5 about the same period in the Ninghe region. Based on the foreshocks with the main fracture plane in the Ninghe region was investigated, and it may be the left-lateral nodal plane of NW.更多还原