大华北第四活动期地震的集中与分散活动

本文通过对大华北第四地震活动期的研究,发现该地区地震有集中活动与分散活动交替出现的特征。在集中活动时,地震主要分布在华北平原中部至渤海湾一带。几次集中活动的位置相对稳定。分散活动时,基本扩散在大华北地区的外围。文中还对大华北地震活动趋势进行了估计。分析认为,未来强震活动区域有可能仍位于上述集中活动主体区域内。

THE CHARCTERISTICS OF SEISMIC CONCENTRATIVE AND DISPERSIVE ACTIVETY OF THE FOURTH ACTIVE PERIOD IN NORTH CHINA

In this paper,the fourth seismic active period is studied in North China.The character- istics of alternate appearance of concentrative and dispersive activety are discovered in this area.The strong earthquakes distributed in central area of the North China Plan to Bohai Bay in concentrative active stage.There is a ralative stabilization area in several concentrative activity stayes.The earthquakas sprend in outer circle in North China in dispersive active stage. In the paper,the seismic active trend is also estimated in North China.