Mapping Onland River Channels up to the Seafloor along Offshore Cide-Sinop in the Southern Black Sea from the Perspective of the Black Sea Flooding

Abstract

In order to investigate the submarine morphology of offshore Cide-Sinop from the perspective of the Black Sea flooding, the rivers, submarine channels and some spatial data were extracted by using General Bathymetric Chart of the Oceans (GEBCO-2014) which is a seamless digital elevation and bathymetry grid (DEM), and Geographic Information System (GIS) software tools. The accuracy of extracted land rivers were controlled with 1/25K topo-maps by using buffer overlay method. The comparisons affirmed that the rivers are on ratio of 75% in 0-400 meters buffer distance. The derived submarine channels with a total of 1548 km length indicate that there is a dendritic drainage pattern with the flow direction from north to the south extending from coast to shelf plain, shelf break and converging toward the abyssal plain respectively in the study area. However, seismic profiles do not indicate any recent delta deposits on the shelf plain. The only some prograded delta deposits are determined at the shelf break in a limited area, where they coincide with the submarine channels derived in this study. These deposits are truncated from their top by an erosional surface which extends over the whole shelf plain. These results indicate that the derived submarine channels do not represent the current flow pattern offshore Cide-Sinop. Instead, they illustrate paleochannels that should be active during the last lowstand time, before the Black Sea Flood and their sedimentary influx should also control the developments of canyons located at the shelf edge at that time. However, the most of the canyons located on the shelf slope are under the influence of both submarine erosion and active tectonics at present.