Abstract The frequency-dependent attenuation characteristics of P-waves (Qα), S-waves (Qβ) and coda waves (Qc) in north-west (NW) Himalaya and its surrounding region have been estimated using 515 micro to moderate earthquakes (2.5 ≤ Mw ≤ 5.0) recorded from January 2008 to November 2015 for a central frequency range (fc) varying from 1.5 to 12 Hz. Average attenuation relationships of Qc, Qα and Qβ found as: Qc = (126.94 ± 37.9)·f (1.122±0.06), Qα = (65.127 ± 5.7)·f(1.1261±0.03) and Qβ = (93.855 ± 3.05)·f(1.1145±0.01) for the region. It is found that the nature and extent of seismic attenuation are different for different seismotectonic belts consisted of various kinds of fault systems distributed into the Indo Gangetic Plain (IGP), the Sub Himalaya (SH), the Lesser Himalaya (LH) and the Higher Himalaya (HH) geotectonic segments beneath NW Himalaya and its surrounding region. Material property heterogeneity beneath the subsurface earth is playing an important role in influencing the degree of release of seismic energy in NW Himalaya and its surrounding region because of varying attenuative property in different geotectonic segments Q − 1 α , β , c HH Q − 1 α , β , c IGP Q − 1 α , β , c SH Q − 1 α , β , c LH . This study may help in better understanding of structural heterogeneities that control the nature and extent of seismogenesis, which in turn may help in assessing seismic hazards through estimates of strong ground motion by computing earthquake source parameters. Our schematic model for NW Himalaya and its surrounding region shed an important light on attenuative characteristics of different tectonic blocks associated with both local and regional fault systems that dictate the source characteristics and potential of earthquake hazards of the region.

中文翻译：

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喜马拉雅西北部及其周边地区地震衰减特征的新见解：对结构异质性和地震灾害的影响

摘要 喜马拉雅西北部 (NW) 及其周边地区的 P 波 (Qα)、S 波 (Qβ) 和尾波 (Qc) 的频率相关衰减特性已使用 515 次微至中等地震 (2.5 ≤ Mw ≤ 5.0) 记录于 2008 年 1 月至 2015 年 11 月，中心频率范围 (fc) 从 1.5 到 12 Hz。Qc、Qα 和 Qβ 的平均衰减关系为：Qc = (126.94 ± 37.9)·f (1.122±0.06)，Qα = (65.127 ± 5.7)·f(1.1261±0.03) 和 Qβ = (93.855·± 3.05) f(1.1145±0.01) 为区域。研究发现，由分布于印度恒河平原（IGP）、喜马拉雅亚（SH）、亚喜马拉雅（SH）的各种断层系统组成的不同地震构造带，其地震衰减的性质和程度是不同的。喜马拉雅西北及其周边地区下方的小喜马拉雅 (LH) 和高喜马拉雅 (HH) 大地构造段。由于不同大地构造段 Q − 1 α , β , c HH Q − 1 α 的衰减特性不同，地下地下物质特性的非均质性在影响喜马拉雅西北部及周边地区地震能量的释放程度方面发挥着重要作用。 , β , c IGP Q - 1 α , β , c SH Q - 1 α , β , c LH 。这项研究可能有助于更好地了解控制地震发生性质和范围的结构异质性，这反过来可能有助于通过计算地震源参数估计强地面运动来评估地震危险。