Abstract

This article continues research of the seismic wave propagation parameters in the North Caucasus. The Q factors of the crust and upper mantle in the vicinity of Makhachkala are obtained, which are compared with the previously obtained Q factors in the vicinity of Sochi, Anapa, and Kislovodsk. According to records of regional (with epicentral distances up to ~300 km) earthquakes (M_W ~ 3.9–5.6) acquired by the Makhachkala seismic station, estimates are obtained for the Q factor of the medium Q (f) in the form Q (f) ≈ f^0.98 (envelope method) and Q (f) ≈ 135f^0.72 (by coda normalization method); the generalized estimate has the form Q (f) ≈ 120 f^0.8 (at frequencies up to ~ 16 Hz). The obtained Q factors in the vicinity of Makhachkala at low frequencies are slightly higher than the estimates obtained for regions of the Northwest Caucasus: the environs of Sochi, Anapa, and Kislovodsk (Q₀ ~ 55–90; n ~ 0.7–1.0). The obtained Q factor estimates are planned to be checked and, possibly, refined by stochastic modeling of local earthquake records.

中文翻译：

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基于Makhachkala地震台记录的东北高加索地壳和上地幔质量估算。

摘要

本文继续研究北高加索地区的地震波传播参数。的Q获得马哈奇卡拉附近的地壳和上地幔的因素，这是与先前获得的相比，Q在索契，阿纳帕，和基斯洛沃茨克附近因素。据的区域的记录（与震中距离可达约300公里）地震（中号_W¯¯由马哈奇卡拉地震站获取〜3.9-5.6），针对所得到的估计值Q的介质的因子Q（˚F在表格）Q（˚F）≈  ˚F ^0.98（信封法）和Q（f）≈135 f ^0.72（通过尾声归一化方法）; 广义估计的形式为Q  （f）≈120 f ^0.8（在高达〜16 Hz的频率下）。将所得到的Q在马哈奇卡拉在低频率附近因素比为西北高加索的区域而获得的估计值稍高：索契，阿纳帕的周围，和基斯洛沃茨克（Q ₀〜55-90; Ñ〜0.7-1.0）。计划对获得的Q因子估计值进行检查，并可能通过对当地地震记录的随机建模进行完善。