Abstract:

Because of the problem of multiple solutions for geophysical inversion, how to reduce the multiple solutions to improve the reliability and accuracy of the results of geophysical inversion is a hot geophysical research topic today. To reduce the multiple solutions of magnetotelluric and seismic data inversion, this study develops a 2-D joint inversion algorithm of magnetotelluric data and seismic data on the base of cross-gradient theory which is proposed by Gallardo and Meju, and the theoretical geoelectric model and velocity model are designed for single inversion and joint inversion, then the 2-D joint inversion algorithm of magnetotelluric and seismic data is verified to be correct and valid. The inversion results show that the above inversion algorithm with cross-gradient constraints can cause the resistivity model and velocity model constrain each other so that the joint inversion result is closer to the reality than the single inversion result. Therefore, the joint inversion is more reliable, which can reduce the multiple solution of geophysical inversion.

Key words: magnetotelluric method, seismic reflection travel time, cross-gradient method, 2-D joint inversion