【摘要】 用1979年7月9日江苏溧阳6.0级地震前后震中附近地区的地震资料,选择与地震活动强度有关的3级以上地震的频次N、b值、η值、A(b)值、Mf值和Ac值等6个参量进行主成分分析,实现对上述参量的有效约减。这6个参量之间具有一定的相关性,各参量在不同时段的变化各有所异,预报效果并不理想。但是根据主成分分析可以得到反应地震强度异常特征的综合指标W,发现该指标在2次溧阳地震前出现明显的异常变化,震后异常恢复。表明综合指标W可以较好地反映地震活动异常增强的特征。文章还对与主成分分析所得结论的有关问题进行了讨论。更多还原

【Abstract】 The primary component analysis method is applied,based on earthquake data around epicenter before and after the Liyang earthquake with MS6.1 occurred on July 9,1979,to select 6 seismicity parameters of earthquake frequency N(ML≥3.0),b-value,η-value,A(b)-value,Mf-value and Ac-value those related to magnitude in order to reduce the parameters.There are some relativity each other in 6 parameters.The variation of these parameters are different,and the anomaly of some parameters is not obvious before the 2 Liyang earthqukes.The synthesis parameter W reflected the characteristics of earthquake magnitude shows obvious anomaly.The anomary are restored after the 2 Liyang earthquakes.It shows that the synthesis parameter W can reflect increment characteristics of seismicity.The other problems of primary component analysis method and conclusion are discussed.更多还原