【摘要】 对东南沿海地区54次中强以上地震(MS≥43/4级以上地震)的时间间隔序列,计算了时间变异系数δ值,利用δ值研究地震的丛集特性;从1943年至今的时间变异系数计算结果为1.2,说明该时间段明显处于丛集状态。对东南沿海地震带通过有序样品序列聚类分析得出了较为合理四个地震活跃幕的划分结果,各个活跃幕地震的累积频次与发震系统内部时间的关系基本符合N=ctd。四个活跃幕的非线性时间结构演化幂指数d变化范围分布在0.6到0.8左右。MS6.0以上的强震也基本符合该关系式。只是其活跃幕演化幂指数d为0.47。更多还原

【Abstract】 There are earthquake crowed together-’cluster’ phenomena distributed on the time axis on the China southeast coastal seismic belt,that were some seismic active periods alternated quiet periods since the 20th century.Using the time-frame variation coefficient method,we discussed some characteristics of the series.Using the ordered samples sequence cluster analysis method on 54 earthquakes occurrence time interval series,we obtained that dividing result of 4 active seismic episodes is more reasonable.Considering another parameter of the earthquakes occurrence time interval :time-frame variation coefficient δ,the calculate result(1.2) of southeast coastal seismic belt above moderate earthquake series(MS≥43/4) since 1943 indicate that is in earthquake cluster situation obviously from that time.For the 4 active episodes in each of them,the accumulate number of earthquakes vs.the earthquakes occurrence time accord with the formula N=ctd.The evolution power exponent d changed from about 0.6to 0.8,the accumulate number of strong earthquakes(M≥6.0)accord with the formula too,but its power exponent d is 0.47.更多还原