Attenuation of high-frequency P and S waves in Garhwal Himalaya, India

作者：Tripathi Jayant N^*; Singh Priyamvada; Sharma Mukat L

来源：Tectonophysics, 2014, 636: 216-227.

DOI：10.1016/j.tecto.2014.08.015

• Body waves
• Seismic attenuation
• Wave propagation
• Garhwal Himalayas
• Quality factor

Tectonics of a region plays important role on the attenuation characteristics of the region. Attenuation characteristics have been estimated to understand the effect of the heterogeneity of the region in a tectonically active Garhwal region of Himalaya. Seismic body wave attenuation characteristics in the region is studied using 234 short-period, seismic observations from local events. The P-wave attenuation (Q(P)(-1)) and S-wave attenuation (Q(S)(-1)) were estimated by applying the state-of-the-art, extended coda normalization method for the frequency range from 1.5 to 24 Hz. Estimates of Q(P)(-1) and Q(S)(-1) decrease from (15.86 +/- 0.90) x 10(-3) and (5.35 +/- 0.51) x 10(-3) at 1.5 Hz to (0.54 +/- 0.11) x 10(-3) and (0.34 +/- 0.06) x 10(-3) at 24 Hz, respectively. The values of Q(P)(-1) and Q(S)(-1) show strong frequency dependence and fit the power-law relation Q(P)(-1)(f) = (27.43 +/- 3.15) x 10(-3)f ((-1.16 +/- 0.06)) and Q(S)(-1)(f) = (8.05 +/- 0.74) x 10(-3)f ((-093 +/- 0.05)), respectively. Obtained results are in the range of those reported for Q(P)(-1) and Q(S)(-1) of the other seismically active regions. The ratio of Q(P)(-1)/Q(S)(-1) is larger than unity in the entire analyzed frequency range and may suggest high degree of heterogeneity in the region.

• 出版日期2014-12-1