İzmir Körfezi ve çevresinin sualti aktif faylari ve depremselliǧi

In order to investigate the active tectonism of the Gulf of İzmir and surrounding area, 975 km of seismic reflection data were collected and processed. After the stratigraphic and structural interpretation of seismic data and their correlation with onland morphological features, N-S to NE-SW trending active transpressional strike-slip faults, reverse faults and some E-W oriented normal faults are mapped in the region. Among these faults, while the N-S oriented Karaburun reverse fault uplifts the Karaburun Peninsula, the N-S oriented Urla reverse fault controls the basement rise along Urla-Uzun Island in İzmir Gulf. The NE-SW trending Tuzla strike-slip fault zone extends from İzmir city to offshore Doǧanbey Promontory and its positive flower structure controls the Seferihisar Ridge. These faults cause an E-W shortening in the region. The normal faults of the study area are mapped offshore Karaburun-Foça, in the inner part of the İzmir Gulf, offshore Alaçati-Teke and Kuşadasi delimiting the southern scarp of the Lesvos basin, the İzmir basin, the northern scarp of the lkaria basin and the continuation of the Küçük Menderes Graben, respectively. Normal faults do not continue for long distances to the east and to the west in the region, they are generally cut by strike-slip faults. The correlation between the active faults and the seismicity of the study area shows that the E-W oriented İzmir fault across İzmir city is not only responsible for earthquake activity of the region but that the N-S, NE-SW oriented Tuzla, Urla and Karaburun faults are also highly responsible for earthquake activity in the last decade, including the 2003 and 2005 Seferihisar and Gulf of Siǧacik earthquakes.