Modeling and uncertainty estimation of gravity anomaly over 2D fault using very fast simulated annealing global optimization

Difficult understanding of gravity effects on the 2D vertical and inclined faults for the delineation of subsurface structure for gravity exploration is slow and cumbersome. Hence, a fast and efficient algorithm is established for the interpretation of gravity anomaly over 2D inclined and vertical fault. The method can simultaneously determine all parameters such as the depth to the top (z) and base (h), dip angle (α), amplitude coefficient (k), and location of the fault plane on the surface (x0) of a hidden thin faulted slab from the observed gravity data. The developed algorithm can effectively interpret all parameters for dipping and vertical fault even though there is no subsurface drilling information. Interpretation of all the parameters suggests that there is no uncertainty for 2D inclined and vertical fault. However, if the detachment tip of the fault is at a larger depth, then the dip of the fault shows some uncertainty. The present code has been applied to non-noisy synthetic anomaly data and Gaussian noisy anomaly. Furthermore, the algorithm was also verified on three field examples from Egypt, and the USA for exploration. The appraised value of all the parameters is found to be in decent agreement with earlier published works and borehole information wherever available.