Document Type : Original Research Paper


1 International Institute of Earthquake Engineering and Seismology, Tehran, Iran

2 Cambridge University, UK

3 Grenoble University, France


Using teleseismic body waves, this paper presents the crustal and lithospheric structure in the central part of the AlborzMountains for the first time. The region has been known as a very active and seismogenic locations in the past, characterized by strong earthquakes and complex structures. Tehran, the capital of Iran, is located on the southern part of the region. The aim of this study is to determine Moho depth and its variation beneath the Central Alborz with high resolution and accuracy. The crustal structure of the Central Alborz beneath 26 broadband stations from a temporary dense seismological network was determined by using recorded data deployed for a period of 4-6 months. We first summarize an analysis of the teleseismic P-wave receiver function beneath each station. Next, we use joint inversion of receiver functions with surface wave dispersion data calculated for the center of network. Results of this research are shown as cross-sections through N-S azimuth of the profiles which passes across the AlborzMountains. Our study shows a thickening in the central part of the AlborzMountains crust down to 55 km relative to 48-50 km crustal thickness beneath northern part of the Central Iran. The crustal thickness is close to 44 km beneath the southern coast of the South Caspian Sea Block. These results are completely unlike with most of the other previous suggested crustal thickness. Based on our results, the AlborzMountains with a high average elevation can be considered with a crustal root.


Akasheh, B., 1975 - Travel time residuals in the Iranian Plateau. Geophys., 41, 281-288.
Allen, M., Jackson, J., Walker, R., 2004- Late Cenozoic reorganization of the Arabia-Eurasia collision and the comparison of short-term and long-term deformation rates. Tectonics, 23, TC2008, doi:10.1029/2003TC001530.
Allen, M., Ghassemi, M. R., Shahrabi, M., Qorashi, M., 2003- Accommodation of late Cenozoic oblique shortening in the Alborz range, northern Iran. J. Struc.Gelog., 25, 659-672.
Ammon, C. J., 1991- The isolation of receiver effects from teleseismic P waveforms. Bull.  Seismol.  Soc. Am. 81, 2504–2510.
Ashtari, M., Hatzfeld, D., Kamalian, N., 2005- Microseismicity in the region of Tehran. Tectonophysics, 395, 193-208.
Asudeh, I., 1982- Seismic structure of Iran from surface and body wave data. Geophys. J. R. Astron. Soc. 71, 715– 730.
Burdick, L. J. & Langston, C. A., 1977- Modeling crustal structure through the use of converted phases in teleseismic body-wave forms, Bull. Seism. Soc. Am. 67(3), 6777-691.
Dehghani, G. A., Makris, J., 1984- The gravity field and crustal structure of Iran. Neues Jahrb. Geol. Palaeontol. 168, 215– 229.
Giese, P., Makris, J., Akasheh, B., Roewer, P., Letz, H., Mostaanpour, M., 1984 - The crustal structure in southern Iran derived from seismic explosion data. Neues Jahrb. Geol. Palaeontol. 168, 230– 243.
Hedayati, A., Brander, J.L., Berberian, M., 1976- Microearthquake survey of Tehran region, Iran. Bull. Seismol. Soc. Am. 66, 1713– 1725.
Jackson, J. A., Priestley, K., Allen, M. B., Berberian, M., 2002- Active tectonics of the SouthCaspianBasin. Geophys. J. Int. 148, 214–245.
Javan Doloei, G., Roberts, R., 2003 - Crust and uppermost mantle structure of Tehran region from analysis of teleseismic P-waveform receiver functions. Tectonophysics, 364, 115-133.
Langston, C. A., 1977- Corvallis, Oregon, crustal and upper mantle receiver structure from teleseismic P and S waves. Bull. Seismol. Soc. Am. 67, 713– 724.
Mokhtari, M., Farahbod, A. M., Lindholm, C., Alahyarkhani, M., Bungum, H., 2004 - An approach to a comprehensive Moho depth map and crust and upper mantle velocity model for Iran. Iranian Int. J. Sci., 5 (2), 223-244.
Pablo Ligorria, J., Ammon, C. J., 1999- Iterative deconvolution and receiver function estimation. Bull. Seismol. Soc. Am. 89, 1395– 1400.
Priestley, K., Tilmann, F., 1999- Shear-wave structure of the lithosphere above the Hawaiian hot spot from two-station Rayleigh wave phase velocity measurements. Geophy. Res. Lett., 26, 1493-1496.
Priestley, K., Baker, C., Jackson, J., 1994 - Implications of earthquake focal mechanism data for the active tectonics of the SouthCaspianBasin and surrounding regions. Geophysics Journal International 118, 111–141.
Rham, D., Priestley, K., Tatar, M., Poul, A., Hatzfeld, A., Radjaee, A., Nowrouzi, G., Kaviani, A., Tiberi, C., 2005- Variation of fundamental mode Rayleigh wave group velocity dispersion in Iran and surrounding region, Eos Trans. Aug., 86(52), Fall Meet. Suppl., Abstract S51A-0984.
Sobouti, F., Arkani-Hamed, J., 1996- Numerical modelling of the deformation of the Iranian plateau. Geophys. J. Int. 126, 805– 818.
Stöcklin, J., 1974 - Northern Iran: Alborz mountains. In: Spencer, A. (Ed.), Mesozoic–Cenozoic orogenic belts: data for orogenic studies. Geological Society Special Publication 4, 213–234.
Tatar, M., 2001- Etude sismotectonique de deux zones de collision continentale: le Zagors Central et l’Alborz (Iran), The`se de l’Universite´ de Grenoble.
Tchalenko, J.S., 1975 - Seismicity and structure of the Kope Dagh (Iran, USSR), Phil. Trans. R. Soc., 278, 1-25.