Morphologic features of the Marmara Sea from multi-beam data

The bathymetrical image of the Marmara Sea (NW of Turkey) was prepared, using data from mainly multi-beam surveys and from various other sources. The Marmara Sea presents a unique and complicated morphological system, which is mainly controlled by the active tectonic regime of the North Anatolian Fault Zone (NAFZ). The sub-bottom morphology of the Marmara Sea consists of a wide shelf area (55% of the total area) and the Marmara Trough, which includes the slopes, ridges and deep basins. The four basins separated by ridges constitute the E–W trending Marmara Trough in an elliptical form. Submarine canyons and landslides constitute the secondary morphological units of the Marmara Sea. The angle and the shape of the slopes are variable in different parts of the Marmara Sea. The linear-shaped slopes bounding the Çınarcık Basin (eastern extremity of the Marmara Sea) and off the Ganos Mountain System (west of Marmara Sea) are characteristic with their high gradient, and resulted from strike–slip fault. The curve-shaped slopes with low angles are considered to be associated with normal fault. E–W-aligned lineaments are morphological expressions of strike–slip faults and can be traced from the Ganos Mountain System through Çınarcık Basin, cutting through the basins and ridges in the western Marmara Trough, and bounding the Çınarcık Basin at the slope–basin transitions. These lineaments reflect a new rupture of NAFZ and must have occurred after the formation of the Marmara Trough.