Rupture process of the M s 7.0 Lushan earthquake determined by joint inversion of local static GPS records, strong motion data, and teleseismograms
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On April 20, 2013, an M s 7.0 earthquake struck Lushan County in Sichuan Province, China, and caused serious damage to the source region. We investigated the rupture process of the Ms7.0 Lushan earthquake by jointly inverting waveforms of teleseismic P waveforms and local strong motion records as well as static GPS observations. The inverted results indicate that the rupture of this earthquake was dominated by the failure of an asperity with a triangular shape and that the main shock was dominated by thrust slip. The earthquake released a total seismic moment of 1.01×1019 Nm, with 92% of it being released during the first 11 s. The rupture had an average slip of 0.9 m and produced an average stress drop of 1.8 MPa. Compared with our previous work that was based mainly on a unique dataset, this joint inversion result is more consistent with field observations and the distribution of aftershock zones.
Key WordsGPS Longmenshan Lushan Earthquake rupture process strong motion
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The Chinese Earthquake Network Center provided the aftershock data. Teleseismic data were downloaded from IRIS, strong motion records were provided by CSMN, and the GPS data were provided by the Institute of Earthquake Science, China Earthquake Administration. The figures were created with GMT software. Dr. Yingjie Yang of Macquarie University provided us with substantial assistance and constructive advice. We here acknowledge our respect for each of those who contributed to our research result. This work was supported by a grant from the Chinese Earthquake Administration (No. 201308013), the National Natural Science Foundation of China (Nos. 41604057, 40974034, and 41021003), and as a key project from the Institute of Geodesy and Geophysics. The final publication is available at Springer via http://dx.doi.org/10.1007/s12583-017-0757-1.
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