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摘要
On August 8, 2017 an M(S)7. 0 earthquake rocked Jiuzhaigou, Sichuan Province. The China Strong-Motion Networks Center (CSMNC) officially released 66 strong-motion recordings collected during this event. Eight of them obtained at stations up to 150 km from the hypocenter, of which the site responses are available, were used to retrieve the source spectra of this earthquake and the frequency-dependent quality factor in the vicinity of the epicenter. The resultant quality factor is Q(f) = 84. 9 f (0.71), indicating the strong non-elastic attenuation of S-waves. Based on the commonly used omega(-2) source model, the grid-searching technique was used to determine the optimum source parameters for this earthquake. The results show that the seismic moment is 9. 42 x 10(18) Nm with the standard deviation 0. 12 on the log(10) scale, corresponding to the moment magnitude M-W =6. 616+/-0. 079, and the corner frequency f(c) is 0. 131 +/- 0. 011 Hz. Based on these values of M-W and f(c), the Brune-type stress drop was estimated as 3. 854 MPa, significantly lower than the average of the global intraplate earthquakes (4. 89 MPa) but higher than that of the M(W)6. 6 Lushan earthquake in 2013.
- 出版日期2017-10
- 单位中国地震局工程力学研究所
