3-d crustal velocity structure of izmir and surroundings [Izmir ve çevresinin 3-B kabuk hiz yapis]

3-d crustal velocity structure of izmir and surroundings has been investigated in the frame of this study by using local earthquake tomography. for this purpose,1723 earthquakes that recorded by 44 stations from 2008 to 2014 have been analyzed. we selected 773 earthquakes which have 7556 p- and 6381 s-phase considering low rms and high phase reading. we formed 3-d horizontal and vertical depth cross-sections for vp and vp/vs models based on tomographic results. moho boundary was detected at -24 km depth in the study area. we have identified four different seismic velocity zones down to upper mantle: thickness of first the layer (called as upper crust) is -7 km and has vp<5 km/sec,second (middle) layer is about between 7-15 km depths having vp -6.2km/sec,thickness of the third one called as lower crust is ~9 km (located from 15 to 24 km) depth representing vp -6.2-7.4 km/sec,and the fourth and last one located beneath crust-mantle boundary is detected deeper than 24 km depths showing greater than vp,7.7 km/sec. three different velocity models were observed in the study area. these are; 1) low vp and low vp/vs,2) low vp and high vp/vs,3) high vp and high vp/vs. high vp and high vp/vs values are observed at different depths of urla and seferihisar regions located at the south of the study area. we conclude that new potential geothermal areas which are not discovered yet,may exist in wide area between seferihisar fault zone and karsiyaka fault zone.