Detailed bathymetry and seafloor image datasets, using multi-beam echo sounder and side scan sonar, around Seonam, Ilsan beach, Ulsan

Abstract

We obtained detailed bathymetry and seafloor image datasets using multi-beam echo sounder and side scan sonar around Seonam at Ilsan beach in Ulsan. The survey was conducted from May 9 to May 12, 2018, using a small vessel. The equipment used for the survey was R2Sonic's Sonic 2020 (Multi-beam Echo Sounder) and EdgeTech’s 4125 (Side Scan Sonar). The detailed bathymetry of the study area shows slightly different topographical features for each part around Seonam. The eastern and southern parts have steep slopes and the depth of the water in the areas deepens away from the surroundings of the submerged bedrock area adjacent to Seonam. The water depth in the western and northern part is shallower with a relatively gentle slope, compared to the eastern and southern parts. The rocky bottom zones are mainly distributed in the eastern part area with the water depth range of 3 to 9 m around the Seonam. Some rocky areas also appear in the western region. Seafloor backscatter image shows irregular, complex reflection patterns of acoustic intensity mainly in the eastern and western adjacent areas around Seonam, and in the northern and southern coastal waters, which are almost identical to the underwater rock zones with shallow water depth. The detailed bathymetry and seafloor image datasets around Seonam, using the multi-beam echo sounder and the side scan sonar, can be used as an essential data for environment habitat mapping.