1976年唐山地震成因解释的一个新模式

指出已有对唐山地震成因解释的不足，综合分析了唐山地震前后的地震现象．认为唐山及周围地区1973～1975年ML4地震密集，而同一时空范围内３级和２级地震并不活跃是最为显著的地震活动特征，并认为这一特征应与区域高应力及地壳介质相对较为完整这一物理实质相对应．假定中国大陆周边的强震活动大体上反映着相应板块对中国大陆作用的强弱，推论20世纪70年代华北地区存在多个动力过程，为唐山地震提供了最基本的力源．进而提出多动力过程和地壳局部弱化模式，以解释唐山地震的成因．这一模式能够较好地解释与唐山地震有关的诸多地震现象． 

A NEW MODEL ON THE CAUSE OF TANGSHAN EARTHQUAKES IN 1976

In this paper the shortages of explanations on the cause of Tanshan earthquakes in 1976 are pointed out. Earthquake phenomena around Tan sha n earthquakes are analyzed synthetically, it is noticed that the most prominen t seismic phenomen on are seismic denseness of M L=4, but M L=3 and M L=2 is not act ive in the same temporal-spatial interval, which occurred from 1973 to 1975. it is pointed tha t the phenomenon should correspond to relative integrity of the crust medium u nder higher regional stress. Assuming that the seismicity in circumjacent region could reflect the jostling e xtent of surrounding plates toward the China continent, it is infered that th ere are multi-dy namical processes in North China region in 1970s, whic h supp ly the basic dynamical source to Tanshan earthquakes. A model of multi-dynamical processes and local weakeing of the crust is proposed to explai n the cause of T anshan earthquakes. This model could unpuzzle many seismic phenomena related to Tanshan earthquakes.