We present the comparison of two leveling methods proposed by Wessel (2010) and Ishihara
(2015) using the geomagnetic data in the Gulf of Aden. The data used in this study were
obtained in the cruises from 1961 to 2001. The data collected over a long period of time may
result in large crossover errors. The reduction of crossover errors is one of the most important
and imperative issues to make magnetic anomaly contour maps. The method proposed by
Wessel (2010) reduces crossover errors at intersections among tracks by an appropriate linear
model. That proposed by Ishihara (2015) consists of adjusting each measurement using the
weighted spatial average of its neighboring data and subsequent temporal filtering. We
compared the two methods for three areas in the Gulf of Aden; one area of the dense data
coverage around the spreading center and two areas of the sparse data coverage off the
spreading center. Our study concluded that the method proposed by Ishihara (2015) reduced
crossover errors more effectively than that by Wessel (2010).