Crustal Structure in the Eastern Part of the Alborz Mountains (Iran) Converted P wave Phases

The Alborz Mountains are part of the Alpine-Himalayan orogenic belt, situated to the south of the Caspian Sea and north of the Central Iran.. The region is undergoing extensive crustal deformation and shortening between the north-central Iran and the rigid South Caspian Basin crust. In this study, we used the P-wave receiver function modeling to investigate the crustal structure beneath the eastern part of the Alborz Mountains data recorded between 2004-2010 in Sari and Semnan seismic networks of short-period seismographs, permanently deployed across the area. We observed clear conversions (Ps) the Moho boundary, and we used them to define a model for the crust of the eastern Alborz. Our analysis indicates a thickening of the crust ~51±2 km beneath the northern part of the eastern Alborz to ~62±2 km beneath the central part of the region, then a thinning of the crust to ~52±2 km towards south of the eastern Alborz Mountains.