| A single geophysical method cannot meet the requirements of exploration accuracy with the increasing complexity of exploration targets and the non-uniqueness of geophysical inversion determine that joint geophysical inversion is imperative. The goal of joint inversion is to acquire a geophysical model that can meet various geophysical data, it means that there is a link between the different geophysical methods, among them wave velocity has obvious relationship with density, so most of joint inversion researches focus on Gravity and Seismic joint inversion. Because of relation between wave velocity and density, so there is a link between velocity interface and density interface, this paper aim at research about 2D interface Gravity and Seismic joint inversion.This paper use reflection travel time and gravity data to carry out joint inversion. In aspect of Gravity forwarding, using 2.5D rectangle subdivide interface model. In aspect of seismic travel time forwarding, using Fast Marching method to calculate travel time, using non-uniform finite difference solve calculate reflection wave travel time on condition of undulating surface or reflection interface, at last, using Linear Travel time Interpolation(LTI) acquire ray path. In inversion aspect, several different objective function is tested by using theoretical model, comparing the inversion result which using different objective function, choosing appropriate objective function. Then analyzing the influence of weight through set various value, concluding that the inversion effect which using normalization objective function we put forward not be affected by weight. In order to reduce inversion time, we adopt parallel arithmetic to solve the problem of long time spent on model forwarding, therefore reduce the time spent on inversion.Finally, we inverse M?re margin region Moho depth by using joint inversion of satellite gravity and OBS Moho reflection travel time, conclude that joint inversion is practicable... |
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