Using GPS data together with geophysical data: A Case study from a seismically active region, Izmir

Essential developments on computer systems and space technologies have given rise to GPS (Global Positioning System) enter into our daily lives. In 1970s, with the advent and rapid development of U.S. Global Positioning System (GPS) a new era in geodesy and geophysics has started. After 1980s GPS has been used for monitoring crustal movements in the world. Likewise, since 1989, GPS data has been and are still being used for earthquake prediction purposes in Turkey. Consequently, in recent years, GPS studies as well as the other geophysical studies have gained importance in tectonically active regions like Turkey. GPS data obtained from episodic observations and/or CORS(Continuously Operating Reference Stations) network provide detailed information that help researchers identify changes which cause earthquakes. Because earthquakes occur as a result of movement of the earth´s crust, today, seismologists and geophysicists are able to measure such movements with high precision with the use of GPS data. In this context, a case study in Izmir and its surrounding, which has active seismicity and tectonism and is located within the N-S trending extensional system in Western Anatolia Region, was performed under the scope of The Scientific and Technological Research Council of Turkey (TÜBİTAK-108Y285) project. Within the framework of this project, GPS observations were performed in Izmir and its surrounding. Then, the GPS velocity vectors were evaluated with microgravity and seismological data. Consequently, in this study, the literature work about the usage of GPS methods in geophysical studies and the information regarding the studies are presented.