Evaluation of self potential data using second and fourth-order derivative analysis

In this theses, firstly, the theoretical SP anomalies (noiseless and noisy) for the selected simple geological structure models such as horizontal cylinder, vertical cylinder and sphere were calculated. Then, the second and fourth derivatives of these anomalies were evaluated by using different window intervals (s), and the structure depth (z) and structure shape factor (q) parameters of model structures such as sphere, horizontal cylinder and vertical cylinder that cause anomalies in the underground were tried to be determined. The numerical second and fourth numerical derivative of self potential (SP) anomalies obtained using sequential window intervals (s) can be used to decide the depth and shape of a buried structure. For each window range (s; for s=1, 2,…, M), the depths are determined using a simple formula for each structure shape factor ( for q=0,1, 0,2, 0,3,…., 1,5). Calculated depths are plotted on a graph corresponding to the structure shape factors. On this graph, for each window range (s), from the intersection point of the curves (or in some cases, from the intersections of the curves) to the (z) and (q) graph axes, the points where the projection in the horizontal and vertical directions intersect the axes, the depth of the structure (z) and the structure shape factor (q) gives the value. The method has successfully determined the depth (z) and structure shape factor (q) values of the structure models used in the calculation of the related anomalies in the evaluation of the second and fourth numerical derivatives of the theoretical SP anomalies (noisy and noiseless) and the field self potential (SP) anomaly data obtained from the articles published in the literature. While the method applied to the digitized data of SP field anomalies obtained from the articles published in the literature achieved the intended success in the second derivative solutions, the intended success in the fourth derivative solutions was not achieved sufficiently. The reason for this is thought to be the selection of the sampling interval and the processing sensitivity of the researcher who performed the sampling during sampling.