摘要
我们对宁夏及邻近地区中强地震前后小震综合断层面解进行了不同时间段及分区的研究,研究结果表明宁夏几次中强地震前,小震综合断层面解的P轴取向有明显的变化,有的偏离区域正常构造应力场的P轴主压应力场的方向,有的求不出结果.震前显示异常的最长时间近四年之久.显然,震前的这种变化对预报未来中强地震的发生是有参考意义的.同时还表明,中强地震后区域应力场有调整过程.
The studies in this paper have.showed that before and after several moderately strong shocks in Ningxia, the strikes of P (main pressure stress) axes have changed distinctly, deviating from the strikes of P axes in normal structural stress field or drawing no conclusions. The longest anomaly before earthquakes can last as long as 4 years. So it is obvious that the variation before shocks can be a significant clew for the moderately strong earthquakes prediction
引文
[1]李钦祖.由单台小震资料所得两个区域的应力场.地球物理学报,1973,16.
[2]李孟銮.宁夏地震现代构造应力场及其与地震活动的关系.地震研究,1986,9(3).