通过对大同地震活动窗自开启以来（1989年10月~2016年10月）的地震频次和应变能进行统计分析，发现大同窗的月频次衰减拟合结果呈现分段交替活动特征，可分为3个活跃时段和2个背景活动时段。当处在活跃时段时，山西和张渤这2个地震活动带的地震密集发生，但在正常背景活动时，2个地震带发生的地震则较少。应变能统计结果表明，鄂尔多斯块体周缘强震对大同窗的地震活动有较直接的影响，显示出强震的震级越大、与大同窗的距离越近，则大同窗出现应变能异常就越早、幅度也越大；另外，大同窗受青藏块体强震的影响较强，而受西太平洋板块俯冲的影响较弱；大同窗应变能在周边块体强震后的反应，可能与其所处的地质构造环境有关，因此对应力场的变化较敏感。

In this paper,we analyze the frequency and strain energy of seismic activity of the Datong window from October 1989 to October 2016. The attenuation fitting result of monthly frequency from the Datong window show the characteristics of segmented alternating activity,including three active periods and two background periods. When the Datong window is in the active period,earthquakes occur intensely in the Shanxi seismic belt and Zhangjiakou-Bohai seismic belt;when it is in the normal background period,less earthquakes occur in the two seismic belt. The strain energy result indicates that strong earthquakes of the Ordos block' periphery has a direct impact on the Datong window;the more magnitude of strong earthquakes and the shorter distance from the window,the earlier the strain energy anomalies appear in the Datong window and the greater the amplitude. Additionally,strong earthquakes of the Qinghai-Tibetan block induce more effect on the Datong window,while that of western Pacific plate has a weak effect on the window. The Datong window after strong earthquakes of surrounding block may be related to the geological and tectonic environment,and therefore it is sensitive to the change of stress filed.

P315

2016年度震情跟踪青年课题（2016010114）、山西省地震局2016年科研项目（SBK-1608）共同资助