Upper-mantle S-velocity structure across the Zagros collision zone resolved by nonlinear teleseismic tomography

作者：Keshvari Forough^*; Shomali Z Hossein; Tatar Mohammad; Kaviani Ayoub

来源：Journal of Seismology, 2011, 15(2): 329-339.

DOI：10.1007/s10950-011-9226-y

• Body waves
• Teleseismic tomography
• Upper-mantle structures
• Zagros collision zone

Non-linear teleseismic S-phase tomography across the Zagros collision zone in southwestern Iran is used to determine a high-resolution image of the upper-mantle structure. The inversion was done using 41 high-quality earthquakes recorded by 19 broad-band and medium-band stations along a 620 km long profile across the collision zone. Smearing from strong crustal velocity anomalies into the upper-mantle is suppressed by travel-time corrections calculated based on a 3-D crustal model for the study area. Our results show that the relatively old and cold Arabian shield has a higher velocity (up to 6% faster, at depths between 70 and 300 km) than the younger lithosphere farther north in Central Iran. These two upper-mantle domains are separated by a sharp near-vertical transition whose surface expression coinciding with the Main Zagros Thrust.

• 出版日期2011-4