The Iterative Inversion Method of the Gravity Interface Based on the Regular-Integral Downward Continuation Method

In computational mathematics, the iterative method is a mathematical procedure. This method uses an initial value to generate a sequence of improving approximate solutions for a class of problems, in which the n-th approximation is derived from the previous ones. The iterative method is widely used to solve complex problems in engineering. In this paper, the iterative method is applied to inverse the subsurface interface with the gravity anomaly. First, the classical Parker-Oldenburg interface inversion formula was introduced and analogized to the downward continuation formula. Then, combined with the regular-integral downward continuation method, the iterative inversion formula of the gravity interface is derived. The iterative mode of the improved method suppresses high-frequency signals effectively. At the same time, there is no need to perform forward calculations in the iterative process. The model test shows that the proposed method can accurately calculate the depth of the interface. Finally, the proposed interface inversion method is applied to the Qinghai-Tibet Plateau, and the calculated Moho interface provides some geophysical data support for the geological interpretation of the area in the future.