On the performance of phase-based filters for enhancing lateral boundaries of magnetic and gravity sources: a case study of the Seattle uplift

Determining lateral boundaries of the potential field source is a common feature in interpreting magnetic and gravity data. There are many different phase based filters to determine the boundaries of the source. The purpose of this study is to compare the performance of phase-based filters such as tilt derivative, theta map, normalized horizontal derivative, tilt derivative of the horizontal derivative, tilt derivative of the total gradient, improved theta and horizontal gradient of a modified version of tilt derivative. In order to obtain optimum results, these filters were tested on synthetic magnetic and gravity anomaly data and also aeromagnetic anomaly from the Seattle Uplift (SU), Washington, United States of America. The results show that the tilt derivative of the horizontal derivative method revealed better detection of the source edges compared to the results by the other filters. These results demonstrate that the tilt derivative of the horizontal derivative method is a useful tool for the qualitative interpretation of magnetic and gravity data.