Investigation of the Sığacık Bay’s displacement characteristic by using GPS and gravity data in Western Anatolia

• Sığacık-İzmir has very complicated tectonic features.
• GPS, microgravity survey results were used.
• Derivatives of Bouguer gravity values were obtained.
• Seismicity of Sığacık was evaluated with together results of GPS and gravity surveys.
• Presence of geodynamic structure with two different directions was found.

Sığacık Bay located in Western Anatolian Region attracts attention as an area with high seismic activity in recent years. The bay and its surroundings locate in a very complex fault system. In the scope of this study, the results belonging to GPS and gravity studies within a wide line including Izmir Gulf in the north, beginning from Sığacık Bay, have been examined.In this study, in order to control tectonic settlements of the area, horizontal and vertical derivative methods have been applied to Bouguer gravity data. Additionally, horizontal and vertical velocities have been calculated from GPS studies in the same region to define the movement characteristic of the Sığacık Bay and its vicinity.As a result, all findings obtained from gravity and GPS studies have been assessed together. An approach has been developed for the geodynamic structure controlling the seismic activity of the region by examining obtained findings with seismological data. Obtained results indicated that the both gravity and GPS methods are useful for defining the tectonically displacement in vertical and horizontal direction and as result of all findings deep structural sources in the region presents itself as a mechanism with two different directions, namely north-west and north-east, in the land beginning from Sığacık Bay.