Inversion Of Fault Parameters Based On Disclination-dislocation Model And Quantum Particle Swarm Optimization Algorithm

There is a close relationship between fault activity and earthquakes.Geodetic observation data are used to retrieve the geometric motion parameters of faults and to analyze the tectonic stress characteristics,then the possibility of earthquake occurrence can be evaluated and the process and mechanism of earthquake rupture can be studied by combining other geophysical data.The in-depth study of faults is not only conducive to a profound understanding of the process of strong earthquake preparation and the movement of nearby regional plates,but also has more guiding significance for the scientific early warning of earthquake disasters.In this paper,Jiuzhaigou is selected as the research area.Two pairs of Sentinel-1A images covering the area are processed to obtain the co-seismic LOS deformation and three-dimensional deformation field in Jiuzhaigou earthquake area.Then,the co-seismic sliding parameters and rotation parameters of Shuzheng fault and Huya fault are inverted by combining the global optimal search intelligent algorithm-quantum particle swarm optimization(QPSO)with the direction-dislocation model.The research contents of this paper include:1?Firstly,the development of dislocation theory and disclination theory is summarized,and elaborate the classical dislocation,disclination and its theoretical model of surface deformation.2?In view of the serious enlargement of the north-south direction error in the direct calculation of the three-dimensional deformation field by using multi-view InSAR,InSAR images of ascending and descending orbit covering Jiuzhaigou earthquake area are processed firstly,and the LOS-direction deformation of the Jiuzhaigou earthquake is obtained.We found that the interferograms of InSAR images of ascending and descending orbits show opposite deformation characteristics.Secondly,by using the visco-elastic spherical dislocation model to simulate the North-South deformation of the earthquake,the three-dimensional co-seismic deformation field in the Jiuzhaigou earthquake area is obtained and compared with the simulated value.Among them,the East-West coseismic deformation RMSE is 3.41 cm,and the North-South coseismic deformation RMSE is 2.57 cm,which shows that thecalculated results are credible.3 ? In this paper,the quantum particle swarm optimization(QPSO)algorithm is introduced to invert fault parameters based on the consideration of the effect of fault rotation on surface deformation.Firstly,the horizontal deformation of self-defined strike-slip,dip-slip and tension-fracture rotation faults on the surface is performed by using the directional-dislocation model.Then,taking strike-slip rotational fault as an example,the sliding parameters and rotational parameters of the fault are inverted by standard particle swarm optimization and quantum particle swarm optimization respectively under the same conditions.The results obtained by the two algorithms are compared and analyzed,and the feasibility of applying quantum particle swarm optimization to geodetic inversion is verified.4?Based on the acquisition of the three-dimensional co-seismic deformation field in Jiuzhaigou earthquake area,this paper combines the directional-dislocation model and applies the quantum particle swarm optimization(QPSO)algorithm with better performance to the inversion of the co-seismic sliding parameters and rotation parameters of the Shuzheng fault and Huya fault.The inversion results show that the coseismic movement of Shuzheng fault is mainly left-lateral strike-slip,with a small amount of tension cracks,and the contribution of Shuzheng fault to the coseismic surface deformation is the greatest.The coseismic movement of Huya fault is obvious in segments and slightly larger in the northern segment.Then the inversion results are forward modeled and compared with the inversion results,the results show that the inversion results have high reliability.