Crust and uppermost mantle structure of Tehran region from analysis of teleseismic P-waveform receiver functions

Teleseismic P-waveform receiver function analysis has been used to estimate the main features of the crust and uppermost mantle structure of the Tehran region. In this study, 20 teleseismic earthquakes that were recorded at the seven stations of Iranian Long Period Array (ILPA) were used to calculate receiver functions. The radial receiver functions are analysed through inverse modelling and forward modelling. The results of modelling show a good match between observed radial receiver functions and synthetic radial receiver functions up to 30 s. Based on this study, the crustal structure of this area is characterised by three main layers: The upper crust has a P-wave velocity between 4 and 5.8 km/s and a 14-km thickness. The results representing the uppermost crustal structure indicate a strong dependency on the lithology around each station. The middle crust has a positive P-wave velocity gradient from 6 to 6.4 km/s down to similar to 30 km depth. A P-wave velocity gradient from 6.4 to 7.5 km/s characterises the lower crust with Moho at 46 +/- 2 km at this area. A low-velocity mantle, with velocity gradually increasing with depth down to similar to 60 km depth, has been revealed beneath the Tehran region. (C) 2003 Elsevier Science B.V. All rights reserved.