河南及邻区地震前中小地震活跃—平静的定量指标研究

Index for activeness and quietness of medium and small earthquakes before main event in Henan and its neighboring region

以累计频度定量计算方法,分区讨论了河南及邻区1970年以来地震活动非线性度ZL值的时间进程曲线,系统计算了M≥5.0级地震前的ZL值,结果表明:开始出现活跃(平静)异常的时间集中在地震前1～2年,结束异常的时间在地震前一年内,集中于0～4个月。同时提出了异常的定量指标以及发震类型。

the nonlinear ZL curves of seismicity in different regions of Henan and its vicinity from 1970 are discussed with accumulative frequency method. The ZL values before M≥5 earthquakes are all calculated.The results show that the activeness (or quietness) anomalies begin 1 to 2 years before an earthquake, and end within one year before the event, concentrating to 0-4 month before. The quantitative index for anomalies and earthquake type are presented.