Modeling of the Foca-Uzunada magnetic anomaly and thermal structure in the gulf of Izmir, western Turkey

The Gulf of Izmir (GoI) is one of the largest gulfs in the Aegean Sea, Turkey. There is a large magnetic anomaly extending in the NE-SW direction between Foca and Uzunada (Uzun Island) in the gulf. Previously, Curie Point Depth (CPD), geothermal gradient, heat-flow and radiogenic heat production maps of the onshore part of the Aegean region were constructed from the aeromagnetic data. In this study, the same maps except radiogenic heat production map are presented for the offshore part and the largest magnetic anomaly in the northern part of the gulf is focused, particularly. As a result, the thermal structure of GoI is clearly defined and according to the results of this study, CPD values were found from 7 km in the NE of Foca to 10 km through the south of the gulf. The geothermal gradient values vary between 50 and 80 degrees C/km. Maximum heat flow values around the anomaly are calculated as 200 and 215 mW/m(2) according to the thermal conductivity coefficients of 2.5 W m(-1)K(-1) and 2.7 W(-)1 K-1, respectively. Although the anomaly is located in the Izmir Gulf; CPD, geothermic gradient, heat flow anomalies are shifted through the north of Foca and Aliaga towns in the Candarli Bay. This prominent anomaly in the Gulf of Izmir is associated with the magmatics that were encountered at 969 m in the Foca-1 well although it was drilled about 2 km away from the outermost closed contour of the magnetic anomaly. The anomaly is also modeled three dimensionally (3D) in this study. In the model map, the top of the causative body is completely located in the outer part of the gulf, and is very shallow at about 0.5 km while its bottom is inclined through the west of Cigli and Menemen. From this viewpoint, it is possible to suggest that the causative body is inclined through the Foca Peninsula. However, its closed contours are in the NE direction, through the Candarli Bay. Top depth of the causative body is also calculated from the basement horizon on the seismic sections crossing this anomaly. Depth calculations are consistent in these sections and confirm the top depths from the modeling study. The basement geometry in the seismic sections also reflects the shape of 3D model geometry, and bottom depth of the magmatics is also verified by the basement depth calculations in seismic sections

Natural and anthropogenic submarine morphologies revealed by high resolution acoustic data in the Gulf of Izmir, western Turkey

This study includes the interpretation of submarine morphological structures using the multibeam echo sounder bathymetry and CHIRP high resolution seismic in the Gulf of Izmir. The faults as the indicator of active tectonics, submarine channels, gas seeps, active and inactive pockmarks are the main natural morphological features in the gulf. Additionally, man-made (anthropogenic) structures like navigation channels, excavation debrises and ships wrecks are also observed. Geomorphological development of the gulf is controlled by the active faults in the Neotectonic period. Therefore, detection of active faults is very critical for the morphology of the gulf where many faults with different orientations have been interpreted on the seismic data. In the central-outer part of the gulf to the W NW, there are some normal faults trending in the N NW and S SE direction, and in the eastern and southern part of the gulf, E-W trending normal faults are evident in the seabed topography

Investigation on the tectonic significance of Izmir, Uzunada Fault Zones and other tectonic elements in the Gulf of Izmir, western Turkey, using high resolution seismic data

Active faults at a range in scales are observed in different directions (E-W, N-S and NE-SW) in the extensional tectonic regime of the Aegean region, western Turkey. However, mechanisms and types of faults in the Gulf of Izmir have not been investigated properly. Tectonic setting in the gulf together with the origin and characteristics of faults were studied in this study by integrating interpretation from various very high resolution acoustic data (multibeam bathymetry and CHIRP very high resolution seismic) acquired in the Gulf of Izmir