利用主成分分析法研究东北地震活动异常

Using the Primary Component Analysis Earthquake Parameters Reduction

选择与地震强度有关的地震频次N(ML≥3.0)、b值、η值、Mf值、A(b)值和AC值共6个参量进行主成分分析,实现对上述参量的有效约简。这6个参量之间有一定的相关性,在不同时段各参量的变化各有所异。根据主成分分析可以得到反应地震强度特征的综合指标W。1970年以来东北14次5级以上浅源地震前W都出现明显的异常变化,震后恢复。这表明综合指标W可以较好地反映地震活动的异常特征。

the primary component analysis is made using 6 seismicity parameters of earthquake frequency N（ML≥3.0）,b,η,A（b）,Mf,Ac,which had relation to the earthquake strenth,it was achieved to reduce the above-metioned parameters effectively.There were some relativities among the 6 parameters and each one was different in distinct stages,but the earthquake intensity synthetic index W can be gained by the primary component analysis.W value showed obvious anomalies before 14 shadow earthquakes occurred in the Northeast China area and returned to normal after that.It showed that the synthetic index W can reflect the anomalous characteristics of the seismicity.