云鹏水电站及其周围地震尾波Q_c值研究

Research of Coda Q_c-Value of Yunpeng Hydropower Station and Its Adjacent Regions

利用云鹏水电站周边5个数字地震台站记录到的2000年1月至2008年12月间的108个地震的数字波形资料,采用Aki单次散射模型,计算了各台站周围423条地震记录的尾波Q0值。结果显示:云鹏水电站地区尾波的Qc值与频率的关系为Qc(f)=90.2f0.94。该地区的Q0值比云南其它构造活动强烈地区的要高,因此属于中等构造活动地区。云鹏水电站蓄水后弥勒台记录到的108个地震的尾波Q0值及分频Qc值有所下降,但下降幅度不大,表明水库蓄水对库区及其附近区域地下介质性质有所影响,但影响的程度有限。

The coda-wave-attenuation-quality factor Q0 in Yunpeng Hydropower Station area and its adjacent regions is estimated using Aki＇s single-scattering attenuation model based on 108 local seismic events recorded by 5 regional digital seismic stations from January 2000 to December 2008. The result shows that the relationship between Qc and f can be described as Qc （f） = 90. 2f 0.94. Compared with the ones in other areas of Yunnan with strong tec- tonic seismic activity, the values are higher in this area with moderate tectonic activity. The Q0 and Qc values declined a little after the Yunpeng reservoir impounded water; this means that the water storage has influenced the medea character in this area, but the effect is limited.