Shear wave velocity structure of Iranian plateau: Using combination of ambient noise cross-correlations (C¹) and correlation of coda of correlations (C³)

We use continuous seismic data recorded between January 2013 and December 2014 by Iranian Seismological Center (IRSC) and International Institute of Earthquake Engineering and Seismology (IIEES) networks. Empirical Green's functions between the vertical components of the station pairs are reconstructed by cross-correlating the seismic noise (C1) and recorrelating the coda of the noise-correlations (C3). The combination of these two methods makes it possible to increase the number of retrieved empirical Green's functions, which improves the spatial resolution of the tomographic imaging. We measure and then invert Rayleigh wave dispersion traveltimes to produce 2-D group velocity maps from a period range of 5-40 s for Iranian plateau. The sensitivity tests of tomography using traveltimes from C1 and C1+C3 indicates that C1+C3 indeed enhances resolution. In general, results from seismic noise imaging show good agreement with the local geological units. The shear wave velocity sections resulting from the Bayesian inversion of dispersion curves are interpreted along four profiles in different directions in order to cover the main tectonics of Iranian plateau down to 60 km depth.