A new insight into seismic attenuation characteristics of Northwest Himalaya and its surrounding region: Implications to structural heterogeneities and earthquake hazards

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−1α,β,cHH Q-1c,α,β (Higher Himalaya) in different geotectonic segments.•Material property heterogeneity beneath the NW Himalaya and its surrounding region is associated with varying attenuative property.•Earthquakes of moderate to strong magnitude for given depth of occurrence are different in different segments of NW-Himalaya due to varying seismic attenuatio