Abstract—Records of local earthquakes obtained at seismic station “Makhachkala” are used for estimating the frequency-dependent quality factor of the Earth’s crust and upper mantle in the eastern part of the North Caucasus. The records of 42 earthquakes with epicentral distances up to ~200 km and magnitudes M ~ 2.4–5.8 have been analyzed. The quality function Q(f) is estimated by coda normalization method which is applicable in different situations and yields reliable Q(f) estimates. With the assumed three-segment geometrical spreading function that is equal to 1/R at distances from 1 to 50 km from the source, 1/50 at distances 50–150 km, and 1/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt R $$\end{document} beyond 150 km, the quality factor is found to be Q(f) ~ 10 f 0.9, which is close to the Q-values previously established for the the medium in the vicinity of Sochi, Anapa, and Kislovodsk. The obtained quality factor estimates can be used for forecasting the parameters of ground motions during the future strong earthquakes in the eastern part of the North Caucasus. In the future studies, these estimates can be refined.

中文翻译：

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根据“Makhachkala”地震台记录估计的北高加索东部地震波吸收

摘要——在“马哈奇卡拉”地震台获得的局地地震记录用于估计北高加索东部地壳和上地幔的频率相关品质因子。分析了震中距达~200公里、震级为M~2.4-5.8的42次地震的记录。质量函数 Q(f) 是通过适用于不同情况的尾数归一化方法估计的，并产生可靠的 Q(f) 估计。假设三段几何扩展函数在距源 1 到 50 公里处等于 1/R，在距源 50 到 150 公里处等于 1/50，和 1/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\ oddsidemargin}{-69pt} \begin{document}$$\sqrt R $$\end{document} 超过 150 公里，发现品质因数为 Q(f) ~ 10 f 0.9，接近于 Q-先前为索契、阿纳帕和基斯洛沃茨克附近的介质确定的值。获得的质量因子估计值可用于预测北高加索东部未来强震期间的地震动参数。在未来的研究中，这些估计可以被完善。这接近于先前为索契、阿纳帕和基斯洛沃茨克附近的介质建立的 Q 值。获得的质量因子估计值可用于预测北高加索东部未来强震期间的地震动参数。在未来的研究中，这些估计可以被完善。这接近于先前为索契、阿纳帕和基斯洛沃茨克附近的介质建立的 Q 值。获得的质量因子估计值可用于预测北高加索东部未来强震期间的地震动参数。在未来的研究中，这些估计可以被完善。