TY - JOUR
T1 - Intrinsic and scattering attenuations of the Sichuan-Yunnan region in China from S coda waves
AU - Li, Tian
AU - Zhang, Lei
AU - Song, Xiaodong
AU - Wang, Qincai
AU - Jiang, Xinyu
AU - Zhang, Jinchuan
AU - Chen, Hanlin
N1 - This research is supported by the Fundamental Research Funds for the Institute of Earthquake Forecasting, China Earthquake Administration (No. 2021IEF0603 ) and the Special Fund of the Institute of Geophysics, China Earthquake Administration (No. DQJB21B32 ). We thank two anonymous reviewers and the AE for the thoughtful reviews, which helped improve the manuscript greatly. Waveform data for this study were provided by the International Earthquake Science Data Center (Doi:10.11998/IESDC). For the calculation code, the Eulenfeld (2020) Qopen is used. The location of historical M≥7 earthquakes were provided by International Seismological Center (2022), On-line Bulletin, https://doi.org/10.31905/D808B830[ 3 ]. Most of the figures were generated using Generic Mapping Tools (GMT, Wessel et al., 2019).
This research is supported by the Fundamental Research Funds for the Institute of Earthquake Forecasting, China Earthquake Administration (No. 2021IEF0603) and the Special Fund of the Institute of Geophysics, China Earthquake Administration (No. DQJB21B32). We thank two anonymous reviewers and the AE for the thoughtful reviews, which helped improve the manuscript greatly. Waveform data for this study were provided by the International Earthquake Science Data Center (Doi:10.11998/IESDC). For the calculation code, the Eulenfeld (2020) Qopen is used. The location of historical M≥7 earthquakes were provided by International Seismological Center (2022), On-line Bulletin, https://doi.org/10.31905/D808B830[3]. Most of the figures were generated using Generic Mapping Tools (GMT, Wessel et al. 2019).
PY - 2024/2
Y1 - 2024/2
N2 - Seismic attenuation is a fundamental property of the Earth's media. Attenuation structure for the complicated geological structures with strong seismicity in the Sichuan-Yunnan region is poorly studied. In this study, we collected 108,399 waveforms of 11,517 local small earthquakes with magnitudes between 1.5 and 3.5 from January 2014 to September 2021 in the Sichuan-Yunnan region and its adjacent areas. We employed an envelope inversion technique for separating the intrinsic and scattering attenuations of the S coda wave, and obtained the intrinsic and scattering attenuation structures for frequencies between 0.25 and 8.00 Hz. The attenuation structures correlate well with the geological units, and some major faults mark the attenuation variations where historic large earthquakes have occurred. The regional average attenuation shows a negative frequency dependence. The average scattering attenuation has a faster descending rate than the average intrinsic attenuation, and is dominant at low frequencies, while at high frequencies the average intrinsic attenuation is stronger. The lateral variation in the intrinsic attenuation is consistent with the variation in heat flow, the scattering attenuation may be related to the scatter distribution and size. The total attenuation is consistent with the previous studies in this region, and the separate intrinsic and scattering attenuation may be useful in understanding regional tectonics and important in earthquake prevention and disaster reduction.
AB - Seismic attenuation is a fundamental property of the Earth's media. Attenuation structure for the complicated geological structures with strong seismicity in the Sichuan-Yunnan region is poorly studied. In this study, we collected 108,399 waveforms of 11,517 local small earthquakes with magnitudes between 1.5 and 3.5 from January 2014 to September 2021 in the Sichuan-Yunnan region and its adjacent areas. We employed an envelope inversion technique for separating the intrinsic and scattering attenuations of the S coda wave, and obtained the intrinsic and scattering attenuation structures for frequencies between 0.25 and 8.00 Hz. The attenuation structures correlate well with the geological units, and some major faults mark the attenuation variations where historic large earthquakes have occurred. The regional average attenuation shows a negative frequency dependence. The average scattering attenuation has a faster descending rate than the average intrinsic attenuation, and is dominant at low frequencies, while at high frequencies the average intrinsic attenuation is stronger. The lateral variation in the intrinsic attenuation is consistent with the variation in heat flow, the scattering attenuation may be related to the scatter distribution and size. The total attenuation is consistent with the previous studies in this region, and the separate intrinsic and scattering attenuation may be useful in understanding regional tectonics and important in earthquake prevention and disaster reduction.
KW - Intrinsic attenuation
KW - scattering attenuation
KW - Sichuan-Yunnan region
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U2 - 10.1016/j.eqs.2023.11.003
DO - 10.1016/j.eqs.2023.11.003
M3 - Article
AN - SCOPUS:85183882879
SN - 1674-4519
VL - 37
SP - 51
EP - 66
JO - Earthquake Science
JF - Earthquake Science
IS - 1
ER -