Imaging of deep density structure of Sichuan Basin and analysis for seismogenic background of the Ms6.0 Sichuan Luxian earthquake on September 16, 2021

In recent years, seismic activity has intensified along the southern margin of the Sichuan Basin. The Ms6.0 earthquake in Luxian County once again challenged the traditional understanding of the maximum possible earthquake magnitude in this region. To investigate key scientific issues such as the deep structural characteristics, seismic distribution, and seismogenic environment of the epicentral area, this study employed multi-scale gravity anomaly analysis and density-focused imaging inversion to obtain multi-scale gravity anomalies and three-dimensional density distribution features of the Sichuan Basin. The research focused on analyzing the deep structure of the Huayingshan Fault Zone and, combined with high-precision measured profiles across the fault zone, explored its relationship with the deep seismogenic mechanism of the Luxian seismic area.