The strong ground motion characteristics of M_S6.0 Luxian，Sichuan，earthquake on 16 September 2021

At 04:33 on September 16, 2021, a M_S6.0 earthquake occurred in Luxian, Luzhou city, Sichuan Province. Based on the 1 320 sets of three-dimensional acceleration recordings from the strong motion network nearby the epicenter, we calculated the ground motion related parameters after routine processing of the recordings. With the Kriging interpolation method, we obtained the spatial distribution maps of PGA, PGV and pseudo-acceleration response spectrum. The results show that there are great differences in the direction of the major axis between the meizoseismal area and the mid-far field, which reflects the characteristics of slow attenuation along the fault strike. By comparing the calculated data with the commonly used attenuation relationship prediction values, we analyzed the attenuation characteristics of PGA and pseudo-acceleration response spectrum of multiple periods with distance. It shows that the PGA value of this earthquake is generally smaller than the predicted value by the attenuation relationship. And the pseudo-acceleration response spectrum shows that the larger the period, the slower the attenuation by comparing with the empirical predicted values. This reflects the local attenuation characteristics of the southeastern Sichuan. We also analyzed the maximum acceleration record obtained from this earthquake. Finally we verified that the local topography and site have significant impact on ground motion.