3D model of active faults in the North-South Seismic Belt
This fault model adopts a three-dimensional modeling method of active fault based on seismic activity. The focal mechanism solutions related to the target active fault are chosen by comparing their internal consistency or the consistency with the collected fault geometry data, and the selected solutions are used to construct the initial fault geometry. The initial geometry is further adopted to determine the earthquake relocation data related to the target fault. Subsequently, these earthquake relocations are employed to refine the fault geometry. Based on this method, a three-dimensional model of 369 active faults (segments) in the North-South Seismic Belt was constructed.
Steps to reproduce
Because the geometric and kinematic parameters of seismogenic faults can be indicated well by focal mechanism solutions and earthquakes are mainly concentrated on active faults, the geometry of an active fault can be modeled based on focal mechanism solutions and earthquake relocations. Our modeling method includes three main steps . (1) First, an initial fault model with a coarse resolution is constructed along the fault strike based on the focal mechanism solution data and the collected initial fault geometry parameters. (2) The relocated epicenters of earthquakes due to the specific active fault are selected under the constraint of the initial fault model. The fault geometries along different cross-sections, which are perpendicular to the fault strike, are fitted based on the relocation data. (3) The three-dimensional fault geometry is modeled by compiling all the fault shapes along different fault-crossing profiles.