The Source Rupture Process and the Strong Ground Motion Estimation of the 2022 Ms6.8 Earthquake in Luding,Sichuan
Firstly,we invert the focal mechanism solutions and source depths of the main shock and some aftershocks of the 2022 Luding Ms6.8 earthquake sequence using the re-gional broadband waveform fitting method.Secondly,we using the finite fault model inversion method and the regional broadband waveform data,the rupture model of the Luding earthquake is inverted,and the distribution of strong ground motion is calculated based on the obtained rupture model.The results show that the hypocenter depth of this earthquake is 6.0 km,and it is a typical high-angle left-lateral strike-slip earthquake.The direction of rupture propagation is mainly along the direction of the fault at about 165° to the southeast,starting from the epicenter and extending from the deep to the shallow part,and then rupturing to the surface.The surface rupture mainly occurred in the area from Moxi to Menghugang,with a length of about 16 km.The duration of the earthquake rupture process is about 20 s,and the energy is mainly released within the first 15 s.The seismic moment released is 1.07×1019 N·m,equivalent to a moment magnitude of Mw6.62.The main rupture occurred between 3～6 s,with a maximum slip of 1.8 m,located about 10 km deep in the southeast direction of the epicenter.In addition,there were two second-ary ruptures at a depth of 11 km in the northwest direction from the epicenter and 18 km deep in the southeast direction,respectively,with a slip of about 0.6～1.0 m.The length of the main rupture is about 20 km,and the length of the two secondary ruptures is 4 km and 8 km,respectively.The distribution of peak ground velocity(PGV)is calculated using the obtained rupture model,and the PGV distribution spreads around the epicentre as the centre,its long axis is consistent with the direction of the earthquake intensity long axis,which is NW-oriented,and the peak ground velocity in the epicentral area is 200～360 cm/s.The villages and towns that incurred substantial damage in the earthquake intensity zone are all located in the article's epicentre.
The 2022 Luding Ms6.8 earthquakeFocal mechanismSource rupture processPeak ground velocity
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万方数据
