赣南地区P波、S波随频率衰减关系研究

Research on Attenuation Relationship of P and S Waves with Frequency in South of Jiangxi Province

利用发生在赣南地区的183次ML≥1.0地震资料,采用尾波归一化方法对寻乌、安远和龙南3个台站的P波、S波品质因子QP和QS值进行了计算,分析了该地区地壳介质的衰减特征。研究结果表明,寻乌(流逝时间35 s)和龙南台(流逝时间40 s)QP值较可靠且值相近,拟合平均值为QP(f)=(20.76+1.67)*f(1.03±0.04),寻乌台和安远台(流逝时间均为21 s)拟合平均值为QS(f)=(18.86+1.46)*f(0.84±0.04)。Q值总体呈现低Q0和高η值的特点,这是构造运动活跃地区的特征体现,也和该地区中强地震比较活跃的特征相符。

Using 183 ML≥1. 0 earthquakes occurred in south of Jiangxi province,we calculate the quality factors for P（ Qp） and S waves（ QS） of the Xunwu,Anyuan and Longnan stations by the extended coda-normalization method,and investigated the seismic attenuation properties of the crust medium in the study area. The results show that the Qpvalue of Xunw u（ lapse time is 35s） and Longnan stations（ lapse time is 40 s） is reliable and close,the average value of the fitting result is QP（ f） =（ 20. 76 ± 1. 67） ＊ f（ 1. 03 ± 0. 04）,and the average value of QSof Xunw u and Anyuan stations（ lapse time is 21s） is QS（ f） =（ 18. 86 ± 1. 46） ＊ f（ 0. 84 ± 0. 04）. The characteristic of Q value indicates low Q0 and high η,which means that the tectonic movement is active,and is consistent with the characteristic of the moderately strong earthquakes which are active in the study area.