Three-dimensional Magnetotelluric Inversion Test Of MT Sounding Data And Research For Visualization

Magnetotelluric sounding method, as one of today's important geophysical methods in detecting electrical structure of the deep Earth and continental dynamics research, is playing an increasingly important role in the deep energy exploration, natural disaster reduction, engineering and other fields. In 2006,the professor Siripunvaraporn in Mahidol Unversity developed exoteric code WSINV3DMT which is based on REBOCC algorithm theory and approach the minimum structure in numerical domain. The code could execute the forward model and inversion algorithm for the space model and impedance data. The work in this paper is mainly based on this program. By compiling accompanied interface program WSINV3DMT_PACKAGE and by debugging and running this code to simulate standard one-dimension,two-dimension,three-dimension model numbericaly,and processing three-dimension inversion with measured MT sounding data. This work will make an important and practical significance in the domestic at achieving a huge success of three-dimension MT inversion method.Research found that the kit combined WSINV3DMT_PACKAGE program has lots of advantages such as being easy to operate,simple and efficient,quick and easy,beautiful appearance and having a strong practical ability and so on, and the core of code WSI3NVDMT program also has a great deal of advantages,for example,it running smoothly,converging fast and otherwise. Generally, the number of iterations lessing than 10 times can meet our requirement. By using the kit and WSINV3DMT program to simulate many half-space underground models. We found the results have a higher resistivity value when doing a simulation for the data of three-dimension low resistivity model,but the results are reverse in simulation for the data of three-dimension high resistivity model. The results of abnormal bady's shape have relationship with the density level of measuring point,the choice of frequent point,the size of abnormal body the depth buried,and the initial model and some other factors. It also enjoys that traits which has truncation effect at measuring point boundary, and enjoys some other characteristics.We also use the measured mainland MT data to carry out three-dimension inversion test,and the results have good shows of the geological structure of LiaoKao tectonic faults and the information of underground low resistance glutenite and the information of tuff rock high resistance glutenite. The research shows that the WSINV3DMT_PACKAGE kit combined WSIN3DMT code has a good three-dimension results and practical application.