【摘要】 本文根据AKi单次逆向散射的尾波理论,应用Herrmann等人推广了的尾波理论模式,并假设Q与频率相关,计算了58-1,63-B和DSL-1三种短周期地震仪的尾波优势频率、尾波形状和尾波斜率作为t^*函数的理论曲线,并利用库区四个台58-1仪器记录的新丰江库区的地震资料,用S-t^*和C-t^*两种方法,估算了新丰江水库区频率约为1.0Hz短周期波的地壳Q₀值,得到Q₀值在170—300之间,平均为230±38;频率相关系数为0.0—0.2。Q₀的平面分布表明,近坝峡谷区具有最低的Q₀值。与其他地区对比后认为,库区属于地质构造相对稳定的地区。 文中还对尾波Q值的估测方法等若干问题进行了讨论。更多还原

【Abstract】 Based on Aki’s theory on single backscattering coda wave in applying the coda theory model developed by Herrmann et al. while assuming that the Q is interrelated with the frequency, theoretic curves are calculated in the paper, taking the predominant coda frequency fp(t*, η), the coda slope C(fp, t*, η) and the shape S(p, t*, η) as function of t* for the model 58-1, 63-Band DSL-1 short-period seismographs used in the Xinfengjiang region-data were obtainedfrom 55 local earthquakes, with magnitudes mostly between 3.0 and 5.0. By applying both methods of S-t* and C-t* on the seismic data reco ded with model 58-1 seismographs at four seismic stations in the Xinfengjiang region, the Qo-value of the earth’s crust at a frequency around 1.0 HZ in the reservoir region is calculated as between 170 and 300, averaging 230±38, and the frequency correlation coefficient being 0.0 to 0.2. Spatial distribution of Q0 indicates that the lowest Q0-value falls on the deep canyon area near the dam. Compared with data obtained in other areas, it is considered that the reservoir region is a relatively stable geologic structure.In addition, the methods of estimating the Q-value of coda waves as well as other issues concerned are also discussed in the paper.更多还原