Gravity data interpretation using the s-curves method

Abstract

An algorithm is developed for a fast quantitative interpretation of gravity data generated by geometrically simple causative bodies. This algorithm utilizes numerical fourth horizontal derivatives computed from the observed gravity anomaly, using filters of successive window lengths to estimate the depth and shape of a buried structure. For a fixed window length, the depth is estimated using a simple formula for each shape factor. The computed depths are plotted against the shape factors on a graph. All points for a fixed window length are connected by a continuous curve (s-curve). The estimated solution for the depth and shape of the buried structure is read at the common intersection of the s-curves. The technique can be applied not only to the true residuals, but also to the measured Bouguer gravity data. The method is applied to synthetic data with and without random errors and two field examples from Egypt and the USA. In all cases examined, the estimated depths and other model parameters are found to be in good agreement with the actual values. © 2007 Nanjing Institute of Geophysical Prospecting.