南天山西段地震尾波Q值研究

The study on seismic coda Q value in the western segment of south Tianshan

摘要:

基于新疆地震台网的数字地震波形资料，采用Aki的地震尾波单次散射模型，选取了南天山西段10个台站周围60km范围内M_S≥2.0的397次地震事件计算并得到了不同台站的尾波Qc值。结果显示，南天山西段尾波Q₀值平均值在140～390之间，其中喀什台和乌恰台Q₀值最低；频率相关系数η的平均值在0.62～1.00之间，拟合平均Q值与对应频率之间的关系结果为Q=261.2±110.8f^0.80±0.28，表明该地区是以低Q₀高η值为特征的构造活跃区。

Abstract:

The coda attenuations below 10 seismic stations in the southern Tianshan region were studied in this paper by using the earthquake waveform data recorded through the Xinjiang Digital Seismic Network. 397 earthquakes with M_S ≥ 2.0 with the epicentral less than 60km around studied stations were used. The result showed that the average coda Q₀ value of the southern Tianshan region is about 190~390 among which Kashgar and Wuqia have the lowest value. The correlation coefficient of mean frequency η is about 0.62~1.00. The relationship between the scattering attenuation and the frequency in the southern Tianshan region can be expressed as Q=261.2±110.8f^0.80±0.28,suggesting that studied region is a tectonic active zone characterized with low Q₀ and high η values.