Three-dimension Slip Velocity Of Faults Inversed By Particle Swarm Optimization

Inversing dynamic parameters such as slip rate of faults with geodetic data, recognizing the geodynamic process of fault slip to discuss the relationship between the crustal movement and earthquake through the ground-based observation, forecasting the earthquake and the geological disaster have important scientific significance.In this paper, a new optimization algorithm-particle swarm optimization (PSO) was introduced. Combined with dislocation model to inverse three-dimension slip velocity with geodetic data and geological information. The main works are summarized as follows:1. The research present situation of the geodesy inversion, dislocation model and PSO were introduced in detail. The model of geodetic inversion by PSO, based on dislocation model was built.2. The slip rate of fault inversion calculation model with single data was given. Added artificial disturbance error to the simulated surface deformation caused by fault movement as real values. Inversed simulated fault by PSO and dislocation model, and compared the result with another two algorithms. The results show that PSO can solve problems of inversion of faults' parameter effectively. It has better reliability and stability than method-Monte Carlo and ant colony optimization.3. Taking Qinling fault and Lintong-chang'an fault for example, used PSO combined with dislocation model and GPS data of 04-07, inversed three-dimension slip velocity of those faults. Then, three-dimension slip of Longmenshan fault with the coseismic GPS data was inversed by the same way. The results showed the single data PSO inversion results were consistent with the geotectonic background, which prove PSO has good reliability in inversing real faults.4. Applied PSO to the model of joint inversion with several kinds of geodetic data. The three-dimension slip of Longshoushan,Huangcheng-Ta' erzhuang,Zhuanglanghe faults were inversed by PSO with the data of GPS,leveling and gravity in northeastern margin of Tibetan plateau, which got the preferable results.