【摘要】 利用文献 [1 ]给出的由深井水位变化反演地壳深层应力变化的方法和华北地区井水位变化资料 ,反演了唐山 7.8级地震前后大区域应力场的动态变化过程 ,分析了应力场的动态调整变化特征 .结果表明 ,唐山地震前 2年 ,在震中区及附近出现应力下降异常区 .临震前异常幅度增大并且异常区向外围扩展 .震后异常区收缩并逐渐消失 .更多还原

【Abstract】 Dynamic change process of stress field of north China before and after the Tangshan M S7.8 earthquake is inverted by using the method inverting stress change of deep layer of the crust by reference[2] and data of well water level.Dynamic change characteristics of the stress field are analyzed.The results show anomalous region with stress decrease was produced in epicenter region and its vicinity two years before the earthquake.The anomalous region expanded outward and anomalous amplitude increased before impending the earthquake.The anomalous region contracted and disappeared gradually after the earthquake.更多还原