Using Gravity Anomaly Of Three-dimensional Fault Parameters Inversion Method

It is popular to identify the fault and inverse the parameters of the fault with Bouguer gravity anomaly in gravity exploration. This is an inversion research of the fault parameters. It will result in a bigger error that we inverse the 3D fault parameters with 2D fault model like before. We will mostly inverse the 3D fault parameters with 3D fault model in this research.For a deeper research and explanation of the fault structure, we design a 3D model and compute a forward formula of theory Bouguer gravity anomaly in the frequency domain. We put forward an inversion method of 3D fault parameters (the top deep and the fault displacement etc) of the quantitative interpretation. We apply not only the Bouguer gravity anomaly data but also the first derivative of the Bouguer gravity anomaly. The characteristic line method is deducted based on the first derivative formula of the 2. 5D model. Its precision is better than the 2D model. And this method is simple and practical, robustness and valuable. Moreover, the model fitting process is deducted based on the 3D model in this paper. In the research and test of the 3D model, we can get the good result with the multi-scale genetic algorithm.The main contents and fruits:(1) We got the theory formula of the frequency domain of the 3D any-angle fault for applying to simulate the gravity anomaly of the fault.(2) Through the theory formula deduction, we deducted the inversion formula of 2. 5D fault model based on the first derivative formula of the gravity anomaly of the vertical fault model.(3) We inversed the parameters of the any-angle fault model by the genetic optimization algorithm.(4) We developed some valuable software of the forward, inversion and continuation and derivation of frequency domain etc.(5) We finished the forward simulation of the single and combination model, and inversed the parameters of the fault.(6) We inversed the fault parameters of the factual gravity data of Yellow sea with this method and got a good result.In this paper, the creativity is that deducted the inversion method of the2. 51) model and the any-angle 3D model. Through the theory model test and factual material process, this method is better in effect than 2D model inversion method and has practical value in application.