本活跃期以来山西地震带地震活动的基本特点

The Basic Features of the Seismicities of Shauxi Earthquake Zone since the Beginning of This Active Period

1815年平陆6^(3/4)级地震揭开了华北本活跃期的序幕,其后的175年中山西地震带虽未发生7级以上强震,但是中强地震频度较高。它们主要分布在大同-平陆北北东向剪切段内。时间序列的幕式活动特点和华北活跃幕的划分是一致的。应变释放速率显示了明显的加速现象。1989年大同-阳高6.1级地震的发生,进一步说明地震活动性的增强。本活跃期尚余的1～2个活跃幕中,山西地震带是值的注意的一个地区。

The earthquake of mag. 6.3/4 in Pinglu County in 1815 raised the curtain on this active period of North China. Although there hadn,t been quakes over mag.7 in Shanrxi Earthquake Zone, the frequency of mid-strong ones were comparatively higher.The quakes were distributed mainly over the shear zone in the direction of NNE between Datong and Pinglu.The feature of episodic activities of the time sequential routine consisted with the division of the active episode in North China. Their strain release rates showed obvious accelerating phenomenon. The occurrence of the earthquake of mag. 6-1 in Datong-Yanggao area further indicated the rising of seismicities. In the rest 1-2 active episodes of this active period, Shanxi Earthquake Zone is one that merits attention.