小江断裂带地震尾波Q_c值特征研究

Research on the Characteristics of Coda Q_c-value in the Xiaojiang Fault Zone

利用小江断裂带及邻区10个数字地震台记录到的地震波形资料,采用Aki单次散射模型,计算了各台站半径60km范围内地震尾波Qc值,分别拟合得到10个台站的尾波Qc和η值,并用10个台站的平均结果得出了小江断裂带及邻区尾波Qc值与频率的关系。结果表明,小江断裂带及邻区总体上属低值Qc区;尾波Qc值空间差异较大,小江断裂带中段为低Qc值,明显低于北段和南段的Qc值。研究了尾波Qc值在时间上的变化与中强地震的关系。

The coda-wave attenuation factor Qc in the Xiaojiang Fault Zone is estimated through the Aki＇s single-scattering attenuation model based on the seismic events from January 2000 to December 2009 recorded by 10 regional digital seismic stations.The events are situated within 60 km from the stations.The relation between Qc and f at the 10 stations are fittted as Qc（f）=Q0f0.81.The Qc-value in the Zone is lower than the ones in the other areas of Yunnan.The Qc-value in the middle part of the Zone is much lower than the ones in the north and the south part of the Zone.The relationship between the temporal variation of Qc-value and the mid-strong earthquakes is studied too.