Análise Numérica do Modelo Direto e da Inversão Gravimétrica 3D

We present a numerical characterization of the ambiguity involved in the relationship gravimetric source signal, showing that different mass distributions in the same volume can produce almost the same signal gravimetric. Additionally, we characterize numerically whereas the degree of ambiguity can not depend on source geometry. We present a new numerical method able to evaluate the effectiveness of the regularized inversion gravimetric estimation of a feature of the deep relief of the basement of sedimentary basins. Presumably decrease the density contrast with depth in sedimentary basins. The proposed method for evaluating the efficacy of gravity regularized inversion attempts to answer two questions: (1) “The gravimetric regularized inversion is able to solve a small oscillation in the relief of the basement at a certain depth” and (2) “What is the smallest volume of a feature in the relief of the basement that can be solved?”. For this direct model was established by calculating the gravity anomaly of sedimentary basins simulated with relief basement characterized by three-dimensional surfaces sinusoidal varying in amplitude and frequency and whose occurrence is simulated at different average depths. The inversion was applied to the modeled gravity anomalies to estimate the volumes of relief features of the basement simulated. Was employed Tikhonov regularization of first order to simultaneously introduce stability and impose a smooth character to the solution estimated by inversion. From the results of the different inversions proceeded to analyze the effectiveness of the numerical inversion. In interpreting these data it was possible to establish a criterion of evaluation to stipulate that the lowest volume feature of the basement at an average depth, with a certain density contrast, can be recovered from a set of gravity data.