Publication Date:
2023-07-04
Description:
The attenuation characteristics in the crust of Garhwal-Kumaun Himalaya region have been estimated using 465 well located earthquakes which were recorded at 52 three-component broadband stations during 2017-2020. We have used extended coda normalization method to estimate the body wave attenuation (Qp and Qs) for five different central frequencies (1.5, 3, 6, 12, and 18 Hz) at each station. The results show strong frequency dependent body wave attenuation in the crust of the study region. To explore the lateral variations of attenuation properties, we have made separate estimation for Garhwal and Kumaun region and obtained the frequency dependent relations as follows: Qp = (30 ± 3).f^(1.05±0.05) , Qs = (143 ± 20).f^(0.88±0.07) for Garhwal region and Qp = (31 ± 1).f^(1.09±0.02) , Qs = (121 ± 11).f^(1.00±0.04) for Kuamun region. Both the regions show strong frequency dependent nature of Q, which may suggest the existence of heterogenities and tectonic complexities in these two regions. The obtained ratios of Qs/Qp are high (〉 1) for the entire analyzed frequency range which are likely to be associated with high degree of heterogenity in the study region. Also, obtained results are well comparable with other reported studies of Qp and Qs for Himalayan as well as different tectonic regions in the world.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
