摘要
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 1 973～ 1 975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 2 0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 .
In this paper the shortages of explanations on the cause of Tangshan earthquakes in 1976 are pointed out. Earth-quake phenomena around Tangshan earthquakes are analyzed synthetically, it is noticed that the most prominent seismic phenomenon are seismic denseness of ML=4, but ML=3 and ML=2 is not active in the same tempo-ral-spatial interval, which occurred from 1973 to 1975. We think that the phenomenon should correspond to rela-tive integrity of the crust medium under higher regional stress. Assuming that the seismicity in circumjacent region could reflect the jostling extent of surrounding plates toward the Chinese mainland, it is inferred that there are multi-dynamical processes in North China region in 1970s, which supply the basic dynamical source to Tangshan earthquakes. A model of multi-dynamical processes and local weakening of the crust is proposed to explain the cause of Tangshan earthquakes. This model could unpuzzle many seismic phenomena related to Tangshan earth-quakes.
出处
《地震学报》
CSCD
北大核心
2001年第5期552-557,共6页
Acta Seismologica Sinica
