LAUSR

In this study, we evaluate the body and coda wave attenuation characteristics within Kyrgyzstan and Tajikistan as part of Central Asia. The selected database consists of 354 broadband seismograms from 179 local earthquakes recorded by 24 different stations within the period of 2015 through 2018. First, coda Q has been inferred for different coda window lengths of 20, 30, 40, and 50 s using the single-backscattering interpretation. The coda Q values increase by increasing the coda window length. We show that coda attenuation properties in Central Asia are better modeled by multiple-scattering and surface wave regimes for long-distance records without invoking any depth dependence of the attenuation properties in the crust. Furthermore, standard errors and convergence of different components’ QC indicate that we can fit envelope records of coda waves much better using a coda window length of 50 s. Therefore, we evaluate average coda quality factor functions as QC = 261 f0.601 and QC = 219 f0.633 assuming multiple-scattering and surface wave regimes for a coda window length of 50 s in the frequency range of 1 to 20 Hz for distances up to 200 km. We also show that the source to site distance of records has a significant impact on coda Q estimates. For a shorter distance range up to 100 km, attenuation attributes of Central Asia are better captured by a single-scattering model. We reevaluate the average coda quality factor function as QC = 222 f0.692 assuming a single-backscattering model for a coda window length of 50 s in the frequency range of 1 to 20 Hz for distances up to 100 km. Moreover, we determine QP = 158 f0.706 and QS = 152 f0.856 with a geometrical spreading function of R−1 using the multiple-station coda normalization method.