Three hundred and thirty-five local earthquakes were processed and the attenuation properties of the crust in the Racha region were investigated using the records of seven seismic stations. We have estimated the quality factors of coda waves ([Formula: see text]) and the direct [Formula: see text] waves ([Formula: see text]) by the single back scattering model and the coda normalization methods, respectively. The Wennerberg’s method has been used to estimate relative contribution of intrinsic ([Formula: see text]) and scattering ([Formula: see text]) attenuations in the total attenuation. We have found that [Formula: see text] and [Formula: see text] parameters are frequency-dependent in the frequency range of 1.5–24[Formula: see text]Hz. [Formula: see text] values increase both with respect to lapse time window from 20[Formula: see text]s to 60[Formula: see text]s and frequency. [Formula: see text] and [Formula: see text] parameters are nearly similar for all frequency bands, but are smaller than [Formula: see text]. The obtained results show that the intrinsic attenuation has more significant effect than scattering attenuation in the total attenuation. The increase of [Formula: see text] with lapse time shows that the lithosphere becomes more homogeneous with depth.

中文翻译：

---

乔治亚州拉查地区地壳的内在衰减和散射衰减

利用7个地震台站的记录，处理了335次局地地震，研究了拉查地区地壳的衰减特性。我们分别通过单背散射模型和尾波归一化方法估计了尾波（[公式：见文]）和直接[公式：见文]波（[公式：见文]）的品质因子。Wennerberg 方法已用于估计总衰减中固有（[公式：参见文本]）和散射（[公式：参见文本]）衰减的相对贡献。我们发现 [公式：见文本] 和 [公式：见文本] 参数在 1.5–24[公式：见文本]Hz 的频率范围内是频率相关的。[公式：见文本] 值从 20 [公式：见文本]s 至 60[公式：见文本]s 和频率。[公式：见正文] 和 [公式：见正文] 参数对于所有频段几乎相似，但小于 [公式：见正文]。所得结果表明，在总衰减中，本征衰减比散射衰减具有更显着的效果。[公式：见正文]随时间推移的增加表明岩石圈随着深度的增加变得更加均匀。