Coda wave attenuation in the Zagros collision zone in southwest of Iran and its tectonic implications

Abstract The Zagros collision zone, located in the southwest of Iran, is experiencing to an immoderately large number of seismic hazards caused by the convergence between the two Arabia and micro-plate of central Iran. The coda Q have been widely used as a vital parameter to investigate the different tectonic features as well as seismic risk assessments. In this study, we have analyzed the spatial variation of coda wave attenuation in the Zagros region, to evaluate the different geological features affecting the seismic wave’s propagation. Our dataset comprises 87295 coda records of about 6421 local earthquakes, with magnitude greater than three recorded by 36 seismic stations in the period of 2006 to 2020. we have applied a very simple regionalization method to mapping spatial distribution of in Zagros area. The spatial distributions of coda Q have a positive correlation with the tectonically and lithology of the interested area. According to the results, three primary elements have been suggested as major controlling factors of variation of seismic Coda waves in different parts of the Zagros area. These factors include: 1) intra-crustal relamination process (crustal channeling), 2) 12 km thickness of sediment-filled by fluid (oil and gas) and 3) Hormoz salt (salt domes). Our results also revealed that the suture zone of Zagros (the Main Zagros Thrust fault, MZT) can be considered as a border in which the distribution of coda wave is different on the sides of the fault.