| Abstrakt: |
In this paper, we select 93 seismic waveform recorded from 2009 to 2011 within 400 km of Chongqing and use the single scattering model to calculate the coda attenuation. Then, based on the multiple anisotropic scattering theory, relative contributions of intrinsic attenuation Qi−1 and scattering attenuation Qsc−1 are separated. Q0 is the coda Q value corresponding to the center frequency which is 1 Hz. The results show that when the length of the coda elapsed time window LW is longer, the Q0 value is larger and the frequency correlation coefficient η is smaller for the same station. When LW is 40, 50, 60, and 70 s, the average Q0 in Chongqing is 182, 213, 242, and 253, and η is 0.99, 0.93, 0.89, and 0.88, respectively. In contrast, the Q0 of Yunnan area is 78 when LW is 60; it indicated less heterogeneity and lower level of seismicity in Chongqing area. The attenuation of these seismic waves is dominated by Qi−1. When the frequency is 2–4 Hz and 4–8 Hz, Qi−1 is obviously greater than Qsc−1, while at other frequencies, the values of the two are similar. Under different LW, the coda attenuation Qc−1 is closer to the total attenuation Qt−1 at 8–16 Hz, and the other frequencies are basically between Qi−1 and Qt−1. Qsc−1 plays a certain role in the coda attenuation in Chongqing. The effective attenuation coefficient α becomes smaller with the increase of the LW. The result is helpful to understand the influencing factors of coda Q value and provide a reference for geological research in Chongqing. [ABSTRACT FROM AUTHOR] |
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