Crustal Velocity Structure in Iranian Kopeh-Dagh, from Analysis of P-Waveform Receiver Functions

In this study, the crustal velocity structure and depth of Moho is determined under the eastern part of Iranian Kopeh Dagh, North-East Iran that is named Hezar-Masjed mountains. The teleseismic waveform receiver functions technique is used to determine crustal thicknesses in this study. ۴۱ teleseismic earthquakes from three broadband seismometers installed in the Iranian Kopeh-Dagh, are used to calculate P-wave receiver functions. Receiver functions for each station are generated from events for a wide range of backazimuths. From analysis of receiver functions at KAR, ZOW and HAM stations, the crustal structure is suggested for the Hezar-Masjed area with a Moho depth of ۴۴-۵۰km. Results indicate three main layers; the upper crust has an S-wave velocity between ۲.۱-۳.۲km/s and a ۱۰ to ۱۲km thickness, a middle crust with S-wave velocity between ۳.۲-۳.۷km/s and a ۲۲ to ۲۵km thickness and the lower crust with S-wave velocity between ۳.۷-۴.۴km/s and a ۱۲ to ۱۵km thickness. An S wave velocity between ۴.۶-۴.۷km/s indicates the velocity of the Moho at ۴۷km on average and varies from ۴۴ to ۵۰km. Deeper Moho is found under the southern station.

Keywords:

Kopeh-Dagh , Hezar-Masjed Mountains , Crustal Structure , Moho Discontinuity , Teleseismic Receiver Functions