A new approach for the interpretation of self-potential data by 2-D inclined plate

Abstract

A new accurate technique has been developed to interpret self-potential (SP) data (d) measured along a profile by a two-dimensional (2-D) inclined plate-like body. The technique solves for the depth (z) to top and half-width (w) of the body, and is based on the second horizontal gradient (SHG) that is calculated at a number of window lengths. Using points symmetrically distributed about the origin point of the SP profile, the scheme derives and evaluates a function F at various window lengths from the measured SP anomaly profile. At a fixed window length (s), the depth corresponding to an assumed half-width is determined by solving a nonlinear equation in the form φ (d, s, w, z)=0. The depths corresponding to all considered windows are then obtained at the assumed width. The standard deviation of these depths is calculated for this width. This process is repeated for various widths. The final solution (the depth and half-width) of the interpretive buried structure is that which achieves the least standard deviation. The validity and accuracy of the new scheme has been demonstrated on theoretical noise free and noisy SP data. It has been successfully applied to two real data, and it is found that the parameters estimated from the scheme described here are in good agreement with those reported in the published literature.