文章基本信息

标题：Temporal variation in scattering and intrinsic attenuation due to earthquakes in East Asia
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作者：Muhammad Zafar Iqbal ; Tae Woong Chung ; Myung Jin Nam 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2021
卷号：11
DOI：10.1038/s41598-021-90781-8
语种：English
出版社：Springer Nature
摘要：Separated attenuation values have not been used in post-seismic variation research, although the scattering attenuation ( Q s −1) parameter that can be used to estimate crustal inhomogeneity due to cracks. In this study, three earthquakes that occurred in Kumamoto ( M7.3), Tottori ( M6.6), and Gyeongju ( M5.8) in 2016 were investigated by applying a multiple lapse time window analysis to seismograms recorded before and after the events. At a low frequency, significantly greater variation of the Q s −1 value was observed than the intrinsic attenuation ( Q i −1) for the Kumamoto earthquake, whereas similarly large variation was observed for the Gyeongju earthquake. For the surrounding Kumamoto earthquake area of increased attenuation, even higher decreases in Q s –1 and Q i –1 were also observed. The increases occurred within a two year-period after mainshock. The large increases in attenuation, corresponding to regions with high peak ground acceleration, were limited to the basin area with an elevation below 500 m. Furthermore, post-seismic increases in attenuation values were found to correlate with the magnitude and length of the quiet periods of the earthquakes. From this study, Q s –1 and Q i –1 were shown as new parameters that can quantitatively measure the post-seismic deformation due to crustal earthquake.