唐山地震的孕育与强震的增震作用
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摘要
唐山地震的孕震构造是唐山菱形块体,在NEE向的区域应力场的作用下,最大剪应力集中在它的对角线上,正好与唐山断裂带相一致,因此成了唐山地震大破裂的始发点.唐山地震前兆演化过程中,有两个显著特点:在空间上有“震中→外围→震中+外围”的转移过程;在时间上有明显的阶段性,前兆异常频次的每一次加速都发生在外围强震发生之后,本文用强震的增、减震理论,推测外围强震的发生对唐山地震的孕育有强化作用,在一个大的区域,强地震的增、减震效应可以形成多个高应力集中区,这些高应力集中区多数都是未来发生强震的地区.
The seismogenic structure of the Tangshan earthquake is the Tangshan rhombo-block, the maximum shear stress accumulated on its diagonal line under the action of NEE regional stress field, which is consitent with the Tangshan fault zone, so it became the initial beginning point of large fracture of the Tangshan earthquake. The evolution process of the precursors of the Tangshan earthquake showed two obvious characteristics: in space, they showed a transfer process from epicenter to outlying area to epicenter plus outlying area ; in time , showing obvious stages, each speedup of the frequency of precursory anomalies all occurred after accurence of a strong earthquake in outlying area. In this paper, the earthquake-increasing and earthquake-decreasing theory is used to infer the strengthening action to the development of the Tangshan earthquake by occurrence of strong earthquakes in outlying areas. In a large area, the earthquake-increasing and earthquake decreasing effect of strong earthquakes can form many high stress concentrated areas. Most of these high stress concentrated areas are the occurrence areas of the coming strong earthquakes.
The seismogenic structure of the Tangshan earthquake is the Tangshan rhombo-block, the maximum shear stress accumulated on its diagonal line under the action of NEE regional stress field, which is consitent with the Tangshan fault zone, so it became the initial beginning point of large fracture of the Tangshan earthquake. The evolution process of the precursors of the Tangshan earthquake showed two obvious characteristics: in space, they showed a transfer process from epicenter to outlying area to epicenter plus outlying area ; in time , showing obvious stages, each speedup of the frequency of precursory anomalies all occurred after accurence of a strong earthquake in outlying area. In this paper, the earthquake-increasing and earthquake-decreasing theory is used to infer the strengthening action to the development of the Tangshan earthquake by occurrence of strong earthquakes in outlying areas. In a large area, the earthquake-increasing and earthquake decreasing effect of strong earthquakes can form many high stress concentrated areas. Most of these high stress concentrated areas are the occurrence areas of the coming strong earthquakes.
引文
[1]梅世蓉主编.1976年唐山7.8级地震.北京:地震出版社,1982.
[2]梅世蓉,等.从唐山地震的前兆特征看强震的孕育过程及综合预报强震的初步探讨.《地震科学研究论文集》.北京:地震出版社,1993.
[3]罗焕炎.京津唐渤及其附近地区现代构造应力场与地震关系的数字模拟.《华北断块的形成与发展》.北京:科学出版社,1980·
[4]张国民,等.高潮期中成串地震间的相互关系及其机理的探讨.地震,1991,(3).
[5]罗兰格,等.地震综合效应场函数及其在地震预报中的应用.华北地震科学,1994,12(4).
[2]梅世蓉,等.从唐山地震的前兆特征看强震的孕育过程及综合预报强震的初步探讨.《地震科学研究论文集》.北京:地震出版社,1993.
[3]罗焕炎.京津唐渤及其附近地区现代构造应力场与地震关系的数字模拟.《华北断块的形成与发展》.北京:科学出版社,1980·
[4]张国民,等.高潮期中成串地震间的相互关系及其机理的探讨.地震,1991,(3).
[5]罗兰格,等.地震综合效应场函数及其在地震预报中的应用.华北地震科学,1994,12(4).
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