Estimation of the Frequency-Dependent Shear Wave Attenuation from Acceleration Spectra of the Ahar-Varzeghan Earthquake 2012

Document Type : Technical Note

Authors

International Institute of Earthquake Engineering and Seismology (IIEES)

Abstract

Two destructive earthquakes occurred on the 11th of August 2012 in the regions of Ahar and Varzaghan, NW Iran. High-frequency strong-motion data of these earthquakes have been analyzed to determine the Qβ (f) and source parameters by inversion of the recorded data. The data from a local network of 21 acceleration records, for the first main shock and 19 records for the second main shock was used to estimate Q-relationship in 30 stations. The seismic hazard map for this region illustrates that most of the area in this province is located within high relative risk and characterized by a large number of heterogeneities. For frequency band of 1 to 20 HZ, the frequency-dependent attenuation for this region found to be Qβ = (94±29) f (0.82±0.05). The authenticity of achieved Qβ (f) relation is checked by comparing the source spectra in various stations with the theoretical spectra. Low values of the coefficient (Q < 200) in the Qβ (f) relation suggest that the region is seismically and tectonically active. The present inversion of strong-motion data gives the source parameters. The corner frequencies and stress drops are calculated as fc1= 0.08[HZ],fc2= 0.11[HZ], Δσ1=77.14[bar] and Δσ2=33.06[bar], respectively. 

Keywords

References

  1. - Mahood, M. (2014) Attenuation of High-Frequency Seismic Waves in Eastern Iran. Pure Appl. Geophysics. 171, 2225–2240.
  2. - Sato, H., Fehler, M.C., and Maeda, T. (2012). ‘Tectonic seismology’. In: Seismic wave propagation and scattering in the heterogeneous earth, 496, Springer, Berlin, page 494.
  3. - Joshi, A. (2006) Use of acceleration spectra for determining the frequency-dependent attenuation coefficient and source parameters. Bulletin of the Seismological Society of America. 96(6), 2165–2180.
  4. - Joshi, A., Kumar, C., Lomnitz, H., Castanos, and Akhtar, S. (2012) Applicability of attenuation relations for regional studies. Geofisical Internacional, 51, 349-363.
  5. - Kumar, A. and Mittal, H. (2015) Earthquake source parameters review in Indian context. Int. J. Civil Struct. Environ. 3(1), 41-52.
  6. - Aki, K. (1980) Attenuation of shear-waves in the lithosphere for frequencies from 0.05 to 25 Hz. Phys. Earth Planet. Inter. 21, 50-60.
  7. - Kumar, N., Parvez, I.A., Virk, H.S. (2005) Estimation of coda wave Attenuation for NW Himalayan region using local earthquakes, Phys. Earth Planet. Inter. 151, 243-258.
  8. - Mahood, M. and Hamzehloo, H. (2009) Estimation of coda wave Attenuation in East Central Iran. J. Seismol. 13, 129-139.
  9. - Erickson, D., McNamara, D.E., and Benz, H.M. (2004) Frequency dependent LgQ within the continental United States. Bull. Seismol. Soc. Am., 94(5), 1630-1643.
  10. - Benz, H., Frankel, A., and Boore, D. (1997) Regional Lg attenuation for the continental United States. Bull. Seismol. Soc. Am., 87, 606-619.
  11. - Farrokhi, M., Hamzehloo, H., Rahimi, H., and Allameh Zadeh, M. (2016) Estimation of Coda Wave Attenuation in the Central and Eastern Alborz, Iran. Bull. Seis. Soc. Am., 106, 1482-1498.
  12. - Mahood, M. and Hamzehloo, H. (2011) Variation of intrinsic andscattering attenuation of seismic waves with depth in the Bamregion, East-Central Iran. Soil Dynamics and Earthquake Engineering, 31, 1338-1346.
  13. - Zafarani, H., Hassani, B., and Ansari, A. (2012) Estimation of earthquake parameters in the Alborz seismic zone, Iran using generalized inversion method. Soil Dynam. Earthq. Eng., 42, 197-218.
  14. - Hassani, B., Zafarani, H., Farjoodi, J., and Ansari, A. (2011) Estimation of site amplification, attenuation and source spectra of S-waves in the East-Central Iran. Soil Dynamics and Earthquake Engineering, 31, 1397-1413.
  15. - Motaghi, K. and Ghods, A. (2012) Attenuation of ground‐motion spectral amplitudes and its variations across the central Alborz mountains. Bull. Seism. Soc. Am., 102, 1417-1428.
  16. - Rahimi, H., Motaghi, K., Mukhopadhyay, S., and Hamzehloo, H. (2010) Variation of coda wave attenuation in the Alborz region and central Iran. Geophys. J. Int., 181, 1643-1654.
  17. - Farrokhi, M. and Hamzehloo, H. (2015) Attenuation of high frequency P and S waves in the crust of Alborz region, Iran. Geophys. J. Int., 188, 645-679.
  18. - Zafarani, H., Rahimi, M., Noorzad, A., Hassani, B., and Khazaei, B. (2015) Stochastic Simulation of Strong‐Motion Records from the 2012 Ahar–Varzeghan Dual Earthquakes, Northwest of Iran. Bull. Seism. Soc. Am., 153, 489-502.
  19. - Andrews, D.J. (1986) Objective determination of source parameters and similarity of earthquakes of different size, Earthq. Source Mech. American Geophysical Union, 37, 259-267.
  20. - Del Pezzo, E., Bianco, F., and Zaccarelli, L. (2006) Separation of Qi and Qs from passive data at Mt. Vesuvius: a reappraisal of the seismic attenuation estimates. Phys. Earth Planet. Int., 159, 202-212.
  21. - Vernant, Ph., Nilforoushan, F., Hatzfeld, D., Abbassi, M.R., Vigny, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, A., Bayer, R., Tavakoli, F., Chery, 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.
  22. - Jackson, J. (1992) Partitioning of strike-slip and convergent motion between Eurasia and Arabia in eastern Turkey and the Caucasus. J. Geophys. Res., 97, 12,471-12,479.
  23. - McClusky, S., Balassanian, S., Barka, A., Demir, C., Ergintav, S., Georgiev, I., Gurkan, O., Hamburger, M., Hurst, K., Kahle, H., Kastens, K., Kekelidze, G., King, R., Kotzev, V., Lenk, O., Mahmoud, S., Mishin, A., Nadariya, M., Ouzounis, A., Paradissis, D., Peter, Y., Prilepin, M., Reilinger, R., Sanli, I., Seeger, H., Tealeb, A., Toksöz, M.N., and Veis, G. (2000) Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. J. Geophys. Res. 105, 5695-5719.
  24. - Copley, A. and Jackson, J. (2006) Active tectonics of the Turkish-Iranian plateau. Tectonics, 25, 165-166.
  25. - Masson, F., Djamour, Y., Van Gorp, S., Chery, J., Tatar, M., Tavakoli, F., Nankali, H., and Vernant, P. (2006) Extension in NW Iran driven by the motion of the South Caspian Basin. Earth planet. Sci. Lett., 252, 180-188.
  26. - Reilinger, R., McClusky, S., Vernant, Ph., Lawrence, Sh., Ergintav, S., Cakmak, R., Ozener, H., Kadirov, F., Guliev, I., Stepanyan, R., Nadariya, M., Hahubia, G., Mahmoud, S., Sakr, K., ArRajehi, A., Paradissis, D., Al-Aydrus, A., Prilepin, M., Guseva, T., Evren, E., Dmitrotsa, A., Filikov, S.V., Gomez, F., Al-Ghazzi, R., and Karam, G. (2006) GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions. J. Geophys. Res., 111, 5411.
  27. - Djamour, Y., Vernant, P., Nankali, H.R., and Tavakoli, F. (2011) NW Iran eastern Turkey present-dat kinematics: results from the Iranian permanent GPS network. Earth planet. Sci. Lett., 307, 27-34.
  28. - Razzaghi, M.S. and Ghafory-Ashtiany, M. (2012) A preliminary reconnaissance report on August 11th 2012, Varzeghan–Ahar twin earthquakes. Report of International Association of Seismology and Physics of the Earth’s Interior, 9, 78-89.
  29. - Xu, Z. and Schwartz, S.Y. (1993) Large earthquake doublets and fault plane heterogeneity in the northern Solomon Islands subduction zone. Pure Appl. Geophys., 140, 365-390.
  30. - Yoshimoto, K., Sato, H., and Ohtake, M. (1993) Frequency-dependent attenuation of P and S waves in the Kanto area, Japan, based on the coda normalization method, Geophys. J. Int., 114, 165-174.
  31. - Kinoshita, S. (1994) Frequency-dependent attenuation of shear waves in the crust of the southern Kanto area, Japan. Bull. Seism. Soc. Am., 84, 1387-1396.
  32. - Papageorgiou, A.S. and Aki, K. (1983) A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion, Part I: Description of the model. Bull. Seismol. Soc. Am., 73, 693–722.
  33. - Brune, J.N. (1970) Tectonic stress and the spectra of seismic shear waves from earthquakes. J. Geophys. Res., 75, 4997–5009.
  34. - Brune, J.N. (1971) Correction. J. Geophys. Res., 76, 5002.
  35. - Hanks, T.C. and Kanamori, H. (1979) A moment magnitude scale. J. Geophys. Res., 84, 2348-2350.
  36. - Rahimi, H., Masominia, N., and Rezapour, M. (2013) Estimation of the kinematic source parameters and frequency independent shear wave Quality factor from acceleration records of the Ahar-Varzeghan earthquake 2012, Journal of Physics of the Earth and Space, 26, 483-502.
  37. - Boore, D.M. (1983) Stochastic simulation of high-frequency ground motions based on seismological models of the radiated spectra. Bull. Seismol. Soc. Am, 73, 1865-1894.
  38. - Atkinson, G. and D.M., Boore (1998) Evaluation of models for earthquake source spectra in eastern North America. Bull. Seismol. Soc. Am., 88, 917-934.
  39. - Yaghmaei-Sabegh, S. (2014) Time–frequency analysis of the 2012 double earthquakes records in north-west of Iran. Bull. Earthq. Eng, 12, 585-606.
  40. - Kim, K.D., Chung, T.W., and Kyung, J.B. (2004) Attenuation of high-frequency P and S waves in the crust of Choong Chung Islands, central South Korea. Bull. Seis. Soc. Am., 94, 1070-1078.
  41. - Safarshahi, M., Rezapour, M., and Hamzehloo, H. (2013) Stochastic finite-fault modeling of ground motion for the 2010 Rigan Earthquake, Southeastern Iran. Bull. Seism. Soc. Am., 103, 223-235.
  42. - JOSHI, A. (2007) Inversion of seismic intensity data for the determination of three-dimensional attenuation structures in the central gap region of Himalayas. Nat. Hazards, 43, 129-146.
  43. - Bindi, D., Parolai, H., Grosser, C., and Karakisa, S. (2006) Crustal attenuation characteristics in northwestern Turkey in the range from 1 to 10 Hz. Bull. Seism. Soc. Am., 96, 200-214.
  44. - Elliott, J.R. Copley, A.C., Holley, R., Scharer, K., and Parsons, B. (2013) The 2011 Mw 7.1 Van (Eastern-Turkey) earthquake. J. Geophys. Res. Solid Earth, 118, 1619-1637.
  45. - Jackson, I., Fitz Gerald, J.D., Faul, H., and Tan, B.H. (2002) Grain-size sensitive seismic wave attenuation in polycrystalline olivine. J. Geophys. Res., 107(B12), 2360.
  46. - Boore, D. and Atkinson, G. (1987) Stochastic prediction of ground motion and spectral response parameters at hard-rock sites in eastern North America. Bull. Seism. Soc. Am., 77, 440-467.
  47. - Press, W.H., Teukolsky, S.A., Vetterling, W.T., and Flannery, B.P. (1992) ‘Numerical Recipes in Fortran.’ In: The Art of Scientific Computing, 2nd ed. Cambridge University Press, Cambridge, UK, pages 340-359.
Journal of Seismology and Earthquake Engineering
Volume 19, Issue 3 - Serial Number 3
August 2017
Pages 231-245

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