The Sea of Marmara is one of the most important active tectonic areasunder the influence of many faults belonging to the North AnatolianFault Zone (NAF), one of the most active tectonic structures of Turkey.It is known that the NAF is divided into three branches named asNorth, Middle and Southern branches within the Sea of Marmara.Among these branches, the middle branch fault system extends alongthe southern shelf of the Sea of Marmara and is distributed over theentire shelf from the west to the east. Therefore, the south of theMarmara Sea is at least as important as the northern part and has thepotential to produce earthquakes. The study area covers the Erdek Bay,located in the west of the Kapıdağ Peninsula in the southwest of theMarmara Sea, and the region between the Marmara Island and KapıdağPeninsula. Therefore, the study area is under the influence of the NorthAnatolian Fault. Today, the models of the Marmara Sea are still thesubject of the discussions by many researchers. Especially, the ideathat the main fault passes from the north has been revealed by manyresearchers and the majority of the attention has been drawn on thismain branch. However, this fault system, which has a very complexstructure in the Marmara Sea, has many effects in the southern partalso. Although there are a lot of researchs about the tectonics of theNorthern branch and the general Marmara Sea, studies for the southernregion are very limited.In this study, in order to reveal the tectonic structure of the south of theMarmara Sea in 2013 and 2014, multichannel seismic and sparkerseismic reflection datasets collected within the scope of the TUBİTAK112Y026 (NSF-TÜBİTAK) project named as SoMAR, jointlyconducted by the Institute of Marine Sciences and Technology ofDokuz Eylül University and the Institute of Lamont-Doherty EarthObservatory of Columbia University.In the northern part of the study area, there is a fault system called theKapıdağ Fault and has strike-slip characteristics. Within the scope ofthe study, it is aimed to reveal the direction of this fault system in theregion in detail. One of the aims of the study is to create a fault map ofthe Erdek Bay of the Sea of Marmara and to reveal the activity of thesefaults since late Quaternary time. The acoustic basement is observedin almost all of the study area. The acoustic basement observed atshallower depths in the south is cut by many faults.The tectonics ofthis region are also studied in detail, including shallow faults anddeeper faults that can be traced to the basement. These faults aremapped among themselves as active and inactive faults. In addition, tothe extent that it can be observed, the horizons on the acousticbasement are also interpreted stratigraphically.</p
