Moho depth variations and Vp/Vs ratio in the Zagros (Iran) from teleseismic converted waves

Abstract

Variation of Moho depth and Vp/Vs ratio beneath the Zagros using 3 years of teleseismic recording at twenty permanent broadband seismic stations of the Iranian Seismological Center (IRSC) where are scattered all over Zagros is presented in this paper. The results of this study are the first receiver function study for the Moho depth beneath these stations on this new dataset. We determine receiver functions by the time domain iterative deconvolution method and Moho depth and Vp/Vs ratio using a modified Zhu and Kanamori method. Our results indicate that the Moho depth beneath the Zagros Mountain Range varies from ~ 30–35 km in western Zagros near the Arabian platform, up to ~ 45 km beneath Central Zagros. In the main Zagros zone, our results indicate a uniform pattern for the Moho depth. The Moho depth reaches ~ 50–54 km beneath stations near Sanandaj-Sirjan Zone (SSZ), indicating a considerable increase of Moho depth from the west toward the east of Zagros. The depth of Moho in the southeast of Zagros is less than other parts of Zagros. We found deepening of the Moho depths beneath stations near the SSZ which can be due to the overthrusting of the crust of Zagros by the crust of central Iran along the MZT. The average Vp/Vs ratio in Zagros is 1.8.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

References

  1. Afsari N, Sodoudi F, Taghizadeh-Farahmand F, Ghassemi MR (2011) Crustal structure of Northwest Zagros (Kermanshah) and Central Iran (Yazd and Isfahan) using teleseismic Ps converted phases. J Seismol 15:341–353

    Article  Google Scholar 

  2. Al-Lazki AI, Sandvol E, Seber D, Barazangi M, Türkelli N, Mohamad R (2004) Pn tomographic imaging of mantle lid velocity and anisotropy at the junction of the Arabian, Eurasian and African plates. Geophys J Int 158:1024–1040

    Article  Google Scholar 

  3. 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. https://doi.org/10.1029/2003TC001530

  4. Ammon CJ, Randall GE, Zandt G (1990) On the nonuniqueness of receiver function inversions. J Geophys Res 95:15303–15318

    Article  Google Scholar 

  5. Berberian M (1994) Master “blind” thrust faults hidden under the Zagros folds: Active basement tectonics and surface morphotectonics. Tectonophysics 241:193–224

    Article  Google Scholar 

  6. Berberian M, King GCP (1981) Towards a palaeogeography and tectonic evolution of Iran. Can J Earth Sci 18:210–265

    Article  Google Scholar 

  7. Blanc EP, Allen MB, Inger S, Hassani H (2003) Structural styles in the Zagros simple folded zone, Iran. J Geol Soc 160(3):401–412

    Article  Google Scholar 

  8. Crotwell HP, Owens TJ, Ritsema J (1999) The TauP Toolkit: flexible seismic travel-time and ray-path utilities. Seismol Res Lett 70:154–160

    Article  Google Scholar 

  9. Dehgani GA, Makris J (1984) The gravity field and crustal structure of Iran. N Jb Geol Paläont 168:215–229

    Article  Google Scholar 

  10. Eaton DW, Dineva S, Mereu R (2006) Crustal thickness and Vp/Vs variations in the Grenville orogen (Ontario, Canada) from analysis of teleseismic receiver functions. Tectonophysics 420(1-2):223–238

    Article  Google Scholar 

  11. Falcon NL (1974) An outline of the geology of the Iranian Makran. Geogr J 140:284–291

    Article  Google Scholar 

  12. Gillard D, Wyss M (1995) Comparison of strain and stress tensor orientation: application to Iran and southern California. J Geophys Res Solid Earth 100(B11):22197–22213

    Article  Google Scholar 

  13. Goldstein P, Snoke A (2005) SAC Availability for the IRIS Community. Incorporated Institutions for Seismology Data Management Center Electronic Newsletter, vol 7, no 1. http://www.iris.edu/news/newsletter/vol7no1/page1.htm

  14. Hatzfeld D, Tatar M, Priestley K, Ghafory-Ashtiany M (2003) Seismological constraints on the crustal structure beneath the Zagros Mountain belt (Iran). Geophys J Int 155:403–410

    Article  Google Scholar 

  15. Hearn TM, Ni JF (1994) Pn velocities beneath continental collision zones: the TurkishIranian Plateau. Geophys J Int 117:273–283

    Article  Google Scholar 

  16. Hessami K, Jamali F, Tabassi H (2003) Major Active Faults of Iran (map). Ministry of Science, Research and Technology, International Institute of Earthquake Engineering and Seismology, Tehran

    Google Scholar 

  17. Hessami K, Nilforoushan F, Talbot C (2006) Active deformation within the Zagros Mountains deduced from GPS measurements. J Geol Soc Lond 163:143–148

    Article  Google Scholar 

  18. Jackson J, Fitch T (1981) Basement faulting and the focal depths of the larger earthquakes in the Zagros mountains (Iran). Geophys J Int 64(3):561–586

    Article  Google Scholar 

  19. Jackson J, McKenzie D (1984) Active tectonics of the Alpine-Himalayan Belt between western Turkey and Pakistan. Geophys J R Astron Soc 77(1):185–264

    Article  Google Scholar 

  20. Jamalreyhani M, Rezapour M, Cesca S, Heimann S, Vasyura-Bathke H, Sudhaus H, Paul Isken M, Dahm T (2019) The 2017 November 12 Mw 7.3 Sarpol-Zahab (Iran-Iraq border region) earthquake: source model, aftershock sequence and earthquakes triggering. EGU Gen Assemb 2020:1068

    Google Scholar 

  21. Kennett BLN, Engdahl ER, Buland R (1995) Constraints on seismic velocities in the Earth from traveltimes. Geophys J Int 122:108–124

    Article  Google Scholar 

  22. Langston CA (1977) The effect of planar dipping structure on source and receiver responses for constant ray parameter. Bull Seismol Soc Am 67:1029–1050

    Google Scholar 

  23. Ligorria JP, Ammon CJ (1999) Iterative deconvolution of teleseismic seismograms and receiver function estimation. Bull Seismol Soc Am 89:1395–1400

    Google Scholar 

  24. McQuarrie N (2004) Crustal scale geometry of the Zagros fold–thrust belt, Iran. J Struct Geol 26(3):519–535

    Article  Google Scholar 

  25. Molinaro M, Leturmy P, Guezou JC, Frizon de Lamotte D, Eshraghi SA (2005) The structure and kinematics of the southeastern Zagros fold-thrust belt, Iran: from thin-skinned to thick-skinned tectonics. Tectonics 24(3)

  26. Motaghi K, Priestley K, Tatar M, Romanelli F, Doglioni C, Panza GF (2015) The deep structure of the Iranian Plateau. Gondwana Res 28(1):407–418

    Article  Google Scholar 

  27. Motaghi K, Shabanian E, Tatar M, Cuffaro M, Doglioni C (2017) The south Zagros suture zone in teleseismic images. Tectonophysics 694:292–301

    Article  Google Scholar 

  28. Ni J, Barazangi M (1986) Seismotectonics of the Zagros continental collision zone and a comparison with the Himalayas. J Geophys Res Solid Earth 91(B8):8205–8218

    Article  Google Scholar 

  29. Ottemöller L, Voss PH, Havskov J (2020) Seismological observatory software: 30 yr of SEISAN. Seismol Res Lett 91(3):1846–1852

    Article  Google Scholar 

  30. Paul A, Kaviani A, Hatzfeld D, Vergne J, Mokhtari M (2006) Seismological evidence for crustal-scale thrusting in the Zagros mountain belt (Iran). Geophys J Int 166(1):227–237

    Article  Google Scholar 

  31. Paul A, Hatzfeld D, Kaviani A, Tatar M, Péquegnat C (2010) Seismic imaging of the lithospheric structure of the Zagros mountain belt (Iran). Geol Soc Lond, Spec Publ 330(1):5–18

    Article  Google Scholar 

  32. Snyder DB, Barazangi M (1986) Deep crustal structure and flexure of the Arabian plate beneath the Zagros collisional mountain belt as inferred from gravity observations. Tectonics 5(3):361–373

    Article  Google Scholar 

  33. Stocklin J (1968) Structural history and tectonics of Iran: a review. AAPG Bull 52(7)

  34. Stocklin J (1974) Possible ancient continental margin in Iran. In: Burke CA, Drake CL (eds) The geology of continental margins. Springer, New York, pp 873–887. https://doi.org/10.1007/978-3-662-01141-6_64

  35. Taghizadeh-Farahmand F, Afsari N, Sodoudi F (2014) Crustal thickness of Iran inferred from converted waves. Pure Appl Geophys 172:309–331

    Article  Google Scholar 

  36. Tatar M, Nasrabadi A (2013) Crustal thickness variations in the Zagros continental collision zone (Iran) from joint inversion of receiver functions and surface wave dispersion. J Seismol 17(4):1321–1337

    Article  Google Scholar 

  37. Tatar M, Hatzfeld D, Ghafory-Ashtiany M (2004) Tectonics of the Central Zagros (Iran) deduced from microearthquake seismicity. Geophys J Int 156(2):255–266

    Article  Google Scholar 

  38. Vernant P, Nilforoushan F, Hatzfeld D, Abbassi M, Vigny C, Masson F, Nankali H, Martinod J, Ashtiani A, Bayer R, Tavakoli F, Ch’ery J (2004) Present-day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and northern Oman. Geophys J Int 157:381–398

    Article  Google Scholar 

  39. Wessel P, Smith WHF (1995) New version of the generic mapping tools released. EOS Trans AGU 76:329

  40. Yamini-Fard F, Hatzfeld D, Tatar M, Mokhtari M (2006) Microearthquake seismicity at the intersection between the Kazerun fault and the Main Recent Fault (Zagros, Iran). Geophys J Int 166:186–196

    Article  Google Scholar 

  41. Zhu H, Kanamori H (2000) Moho depth variation in southern California from teleseismic receiver functions. J Geophys Res 105:2969–2980

    Article  Google Scholar 

Download references

Acknowledgments

We thank the editor and anonymous reviewers for their constructive comments and suggestions. The seismic data used in this study were obtained from the Iranian Seismological Center (IRSC, http://irsc.ut.ac.ir/). We used the computer programs of SEISAN (the earthquake analysis specialized, http://seisan.info), SAC (Seismis-Analysis-Code, http://ds.iris.edu/ds/nodes/dmc/forms/sac/), and Taup package (http://www.seis.sc.edu/TauP/) for data processing and GMT (Wessel and Smith 1995) for plotting.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Afsaneh Nasrabadi.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Shiranzaei, G., Nasrabadi, A. & Sepahvand, M. Moho depth variations and Vp/Vs ratio in the Zagros (Iran) from teleseismic converted waves. J Seismol (2021). https://doi.org/10.1007/s10950-021-09986-z

Download citation

Keywords

  • Moho depth
  • Receiver function
  • Vp/Vs ratio
  • Zagros