【摘要】 本文运用构造、前兆二判式鉴别了唐山跨断层短水准形变异常,并论述了卢龙M_L6.2级地震前的中期异常和短临前兆特征。以此为据,阐明了这次地震是在1981年下半年华北区域应力场明显加强时,唐山7.8级地震的发震断层反向逆冲异常运动所造成的。 宁河、唐山、东台子三处短水准形变异常的相应出现,再次表明即使埋设在地壳运动强烈区土层中的跨断层短水准测线亦有较好的监测地震的能力,而其所受干挠通常是可以识别和排除的。更多还原

【Abstract】 Based on appreciation of the anomalies observed by the Tangshan shortrange leveling across the fauIt using two discriminant(1) for tectonics and precursor, and discussion on behavior of the middle-term anomaly and short imminentterm precursor before the Lulong earthquake(m_L=6.2) it is explained that this earthquake is caused by an inverted anomaly thrusting of the Tangshan seismic fauIt in vertical direction When the stress field of North china enhanceso bviously in the later half of 1981.The anomalies from the Ninghe, Tangshan and Dongtaizi short-range leveling taken place correspondently. It is again shown that the short-range Leveling across the fauIt have an ability to monitor earthquake even if those benchmarks are buried in the soil stratum Within the region of strong crustal motion, and the disturbances of benchmarks in the soil stratum can usually be recongnized and eliminated.更多还原