Investigation of the topography effect on the shape and polarity of the magnetic anomalies

Ground magnetic surveys are frequently conducted in geophysical explorations. These surveys may be implemented in rough topographical conditions, but usually the altitude of the survey is considered to be flat while interpreting. In this study, we make a conceptual study on the physics of the magnetic problem considering different topography conditions for the survey, by the modelling of the 2D and 3D synthetic sources beneath gently to rugged ground topographies. The results show that the amplitude and polarity of the magnetic anomalies can be varying significantly, where the survey surface is not flat. Variations of the magnetic anomaly can be misinterpreted in determining the dip angle and magnetization of the source body. As a consequence, the topography of the survey surface should be considered during the interpretation. Such an effect is also studied on the Damavand volcano with a severe topography in northern Iran.