Crustal Structure from Joint Inversion of Receiver Function and Surface Wave Dispersion beneath Duhok, NW Iraq

Abstract

In 2007, a Guralp CMG-3ESPD broadband seismic station was installed in Duhok northwest of Iraq in collaboration with Duhok University. Duhok area is located in the seismically active collision zone, which represents the continental-continental collision boundary between the Arabian and Eurasian plates. Since then, seismic data has been flowing and continuously analyzed and archived. The data from this station has been used in this study to derive a crustal velocity structure beneath Duhok area. The crustal velocity structure beneath Duhok station was estimated by joint inversion of teleseismic P-wave receiver functions and surface (Rayleigh) wave group velocity dispersion. Herrmann, 2006, Computer Program in Seismology, 3.30 (CPS) was used to estimate the individual receiver functions, the fundamental-mode Rayleigh wave group velocities, and simultaneously invert the receiver function and the Rayleigh wave group velocity dispersion curve for planed layered structure. The inversion results show that the crustal structure beneath Duhok station has two distinct discontinuities; one around 18-20 km depth with shear wave velocity of 3.52 km/s, which represents the Conrad discontinuity, and the second one around 42-44 km with shear wave velocity of 4.05 km/s, which represents the Moho discontinuity.