3-D Upper crustal velocity structure of the Inner Gulf of Izmir from ambient noise tomography

This study aims to reveal upper-crustal velocity structure of Inner part of Izmir Gulf by using ambient noise tomography. One-year noise data have been used from 17 stations belong to IzmirNET. Rayleigh wave group velocities which present good signal/noise ratio have been obtained from dispersion curves by using multiple filter technique. Results have been mapped for 2, 4 and 6 s period intervals. Then, shear wave velocities have been obtained from the inversion of group velocity by using local dispersion curves belongs to same periods. Low velocity areas representing alluvial deposits beneath Inner part of Izmir Gulf, have been precisely observed down to 3 km on group and shear wave maps. Added to this, it is also detected not only the existence of low velocities but also high values in the depth slices of inner part of the Gulf. This method may provide precise and high resolution images of crustal structure and upper mantle by using ambient noise tomography without seismic events. It can be applied in the future to the Aegean Region, Turkey or neighbouring countries by using broad-band data set.