Edge detection and depth estimation of Lake Sapanca, Eastern Marmara Region, from high-resolution magnetic data

The present study aims to determine submarine structural elements by analysing high-resolution magnetic data sets and to examine the impact of geological surface structures characterizing Lake Sapanca. Lake Sapanca is located on the northern branch of the North Anatolian Fault Zone. The study area and its immediate surroundings are located within the most active tectonic structure of Turkey. A magnetic study was carried out in Sapanca Lake to reveal the structural elements that caused the formation of the lake. Diurnal corrections were applied to the magnetic data. During the analysis of the marine magnetic data set, there are variations in the mean field level of the magnetic field caused by the routing effects of ship noise on the measurements. To eliminate this noise effect, directional correction was performed. Then, de-stripping correction was also applied. It is essential to estimate the boundaries and depths of the structural features of the region. In order to elucidate the structural features of the region, different techniques such as tilt angle derivative, the total horizontal derivative of tilt angle derivative, Euler 2D deconvolution, horizontal gradient magnitude, and source edge detection were applied to magnetic data. 2-D modelling using GM-SYS in Oasis Montaj were performed. These techniques identified and mapped the edges of anomalous sources related to magnetic data corresponding to geological elements in the study area. The results allow us to image the submarine lineaments for the survey area. These structural lineaments are in E–W, NE–SW and NW–SE trends. These lineaments in our results are quite compatible with the faults in previous geophysical results. The E–W trending lineaments are related to the E–W trending faults in the region.