Characterisation of shallow sediments in an urban area from inversion of P,Sv and Sh arrivals

In this work we present an analysis of P, Sv and Sh seismic velocities using the tomographic inversion of the first arrivals. The data used in this study are four 2D seismic lines, acquired in the urban area of Kaštela, (Croatia). For each line we picked and inverted the first arrivals of P, Sv and Sh components obtaining the corresponding velocity sections. Then, we analyzed the ratio between these velocities to better characterize the underground sediments of the inversigated area. The results showed the presence of a consolidated subsoil combined with an anisotropic effect of the buried layers, in particular the general high VSv/VSh ratio, obtained from this analysis, suggests a possibile sub-vertical trend of the flysch under the quaternary coverage characterized by an averaged strike perpendicular to the main tectonic movement direction of the area.