Numerical simulation of fault slip and its dynamic source in the main fault zone of Taiyuan Basin

There are three earthquakes which magnitude over 6 have been recorded in Taiyuan Basin located Shanxi seismic belt which has high seismicity. The tectonic activity of Taiyuan basin is mainly controlled by the Jiaocheng fault and Taigu fault near Taiyuan city, So the potential seismic risk is concerned. The previous research results show that the fault slip rate is directly related to the magnitude of the earthquake, and the larger fault slip rate indicates higher seismic risk. In this research, geological and geophysical data are conclude to construct a finite element model of Taiyuan Basin to simulate the fault slip of Jiaocheng fault and Taigu fault after long term tectonic evolution, the stress field is simulated to compare with the focal mechanism of small earthquakes to analyze the dynamic source of Taiyuan basin tectonic activity. The results show that the extrusion of the Ordos block from west to East is the main source of tectonic activities in the Taiyuan basin. The extrusion of Ordos block is the main cause of stress in this area shows tensile property in the north-west direction and compressive property in the north-east direction in Taiyuan Basin. In addition, the slip state simulation results show that the Jiaocheng fault slip rate is higher than that of the Taigu fault, the slip rate of northern Jiaocheng fault is higher than that of southern Jiaocheng fault. (paper)