Morpho-structural setting of the eastern part of the Aegean Sea (Kos-Nisyros-Tilos-Gökova region) revealed by high-resolution bathymetry

A digital terrain model was created and interpreted by using two bathymetric data sets from the Kos- Nisyros-Tilos and Gökova regions respectively. First group of data was acquired as part of the scientific program "GEOWARN" in 2000 and the second group was collected by the Turkish Navy, Department of Navigation, Hydrography and Oceanography in 2005. Two data sets were conventionally processed separately, then merged and re-gridded with 20 m cell size using open source software MB-SYSTEM. Kos-Nisyros-Tilos constitutes a large tectonic graben divided into three basins with 600 m average depth. This graben is penetrated by a complex volcanic group forming the volcanic islands of Nisyros, Pachia, Pergoussa, Yali and Strongyli and small intra-volcanic basins with less than 350 m of depth. This middle zone represents an uplifted tectonic horst above sea-level separating the large graben zone into two adjacent grabens to the north and to the south. Two submarine plains and ridges were mapped as the main morphological features of the Gulf of Gökova. Strike-slip faults, reverse faults, and folds constitute the active features in the gulf. Of these, the Gökova strike-slip fault zone intersects and displaces all WNW-ESE-oriented submarine plains and ridges.