Source and Strong Ground Motion Parameters Estimation of the November 12, 2017, Sarpol-e Zahab, Kermanshah Earthquake Using Recorded Accelerograms of Iran Earthquake Strong Motion Network

Document Type : Research Article

Authors

Road, Housing & Urban Development Research Center, Tehran, Iran

Abstract

On Sunday, November 12, 2017, a strong earthquake with local magnitude of Mn7.3 occurred in the border region between Iran and Iraq in vicinity of the Sarpol-e Zahab town. Unfortunately, this catastrophic event caused many causalities, thousands of injured and vast amounts of damage to the buildings, houses and infrastructures in the epicentral area. The earthquake epicenter was located about 10 km south of Ezgeleh in the Zagros seismotectonic zone. This earthquake was recorded by 113 stations of Iran Strong Motion Network (ISMN) across the country. The nearest station to the epicenter of the earthquake was Sarpol-e Zahab (SPZ) station at a distance of about 39 km. In this research, the source parameters of the earthquake including the seismic moment (M0), the moment magnitude (M) and the corner frequency (fc) were estimated using two methods of Andrews (1986) and inversion of the displacement spectra based on the Brune source model in the frequency domain using ISMN strong motion data. Additionally, the frequency independent quality factor (Q), the source radius (r) (considering a hypothetical circular source), and the stress drop of the earthquake (∆σ) were calculated. The above mentioned values were calculated based on two time windows: the S-wave window and the whole trace window for both methods. The moment magnitude of the event is M7.4 based on the displacement spectra inversion for the whole trace window and M7.3 based on the S-wave window. The estimated value for both windows using the Andrews (1986) methodis M7.3. The estimated M values are in excellent agreement with the reported values. The calculated corner frequencies are from 0.13 to 0.17 Hz and the estimated source radii of the event using both methods are in the 9-11.5 km range. Moreover, the estimated stress drops are in the range of 376 to 572 bar. Ultimately, the strong ground motion parameters were investigated. Using a band-pass filter, all recordings were filtered and their acceleration, velocity and displacement time histories along with their response spectra were extracted, then the peak ground acceleration (PGA), velocity, and displacement of this earthquake were estimated. The PGA recorded at SPZ station on horizontal and vertical components (uncorrected data) are about 684, 554 and 385 cm/s2, respectively. Interestingly, there are two clear packets of energy in the recorded time histories of the Sarpol-e-Zahab, Kerend and some other stations that possibly indicate two sequential failures or two simultaneous seismic events. Considering the magnitude of the event, comparison of the observed values of maximum ground acceleration and velocity with the predicted values by ground motion predication equations presented by Boore et al. (2014), suggests that these equations are appropriate for the region.

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References

آمبرسیز، ن و ملویل، چ. پ.، 1370، تاریخ زمین‌لرزه­های ایران، ترجمه ابوالحسن رده، نشر آگاه، تهران.
سازمان پرشکی قانونی کل کشور، فهرست اسامی جانباختگان زلزله استان کرمانشاه، 28 آذر 1396 (http://www.lmo.ir/index.php).
شجاع­طاهری، ج.، ناصریه، س.، مقدادی، ا. و غفرانی، ه.، 1384، تعیین مقیاس بزرگی محلی، ML، بزرگی ممانی، Mw و روابط تجربی بین آنها در فلات ایران با استفاده از شتاب­نگاشت­ها: مهندسی ساختمان و علوم مسکن، 3(7)، 1-12.
مرکز لرزه­نگاری کشوری، http://irsc.ut.ac.ir/.
مرکز زلزله­شناسی اروپا و مدیترانه، https://www.emsc-csem.org/.
مرکز ملی اطلاعات زلزله آمریکا، https://earthquake.usgs.gov/.
Abercrombie, R., 1995, Earthquake source scaling relationships from 1 to 5 ML using seismograms recorded at 2.5 km depth: Journal of Geophysical Research, 100, 24015–24036.
Ambraseys, N., and Moinfar, A., 1973, The Silakhor, Lurestan, earthquake of 23rd January 1909: Annals of Geophysics, 26, 659–678.
Aki, K., 1966, Generation and propagation of G waves from the Niigata earthquake of June 14, 1964, Part 2, Estimation of earthquake moment, released energy and stress-strain drop from G wave spectrum: Bulletin of the Earthquake Research Institute, 44, 73–88.
Aki, K., 1972, Earthquake mechanism: Tectonophysics, Elsevier B. V., 13, 423-446.
Andrews, D. J., 1986, Objective determination of source parameters and similarity of earthquakes of different size, in Das, S., Boatwright, J., and Scholz, C. H., (eds.), Earthquake Source Mechanics: American Geophysical Union, Washington, D.C., 259-267.
Berberian, M., 2005, The 2003 Bam urban earthquake: a predictable seismotectonic pattern along the western margin of the rigid Lut Block, Southeast Iran: Earthquake Spectra, 21, S35–S99.
Boatwright, J. A., 1980, A spectral theory for circular seismic sources: Simple estimates of source dimension, dynamic stress drop and radiated energy: Bulletin of the Seismological Society of America, 70, 1–27.
Boore, D. M., Stewart, J. P., Seyhan, E., and Atkinson, G. M., 2014, NGA-West 2 equations for predicting PGA, PGV, and 5%-damped PSA for shallow crustal earthquakes: Earthquake Spectra, 30, 1057-1085.
Brune, J. N., 1970, Tectonic stress and the spectra of seismic shear waves from earthquakes: Journal of Geophysical Research, 75, 4997–5009.
Brune, J. N., 1971, Correction: Journal of Geophysical Research, 76, 4997–5009.
Chin, B., and Aki, K., 1991, Simultaneous study of the source, path, and site effects on strong ground motion during the 1989 Loma Prieta earthquake: A preliminary result on pervasive nonlinear site effects: Bulletin of the Seismological Society of America, 81, 1859-1884.
Danciu, L., Sesetyan, K., and Demircioglu, M., 2017, The 2014 earthquake model of the Middle East: seismogenic sources: Bulletin of Earthquake Engineering, 15, 1–32.
Di Bona, M., and Rovelli, A., 1988, Effects of the bandwidth limitation on stress drops estimated from integrals of the ground motion: Bulletin of the the Seismological Society of America, 78(5), 1818–1825.
Eshellby, J. D., 1957, The determination of the elastic field of an ellipsoidal inclusion and related problems: Proceeding of the Royal Society of London, series A, 241, 3763-396.
Feng, W., Samsonov, S., Almeida, R., Yassaghi, A., Li, J., Qiu, Q., Li, P., and Zheng, W., 2018, Geodetic constraints of the 2017 Mw 7.3 Sarpol-e Zahab, Iran earthquake, and its implications on the structure and mechanics of the Northwest Zagros Thrust-Fold Belt: Geophysical Research Letters, 45, 6853-6861.
Gallo, A., Costa, G., and Suhadolc, P., 2014, Near real-time automatic moment magnitude estimation: Bulletin of Earthquake Engineering, 12, 185–202, doi 10.1007/s10518-013-9565-x.
Ghods, A., Rezapour, M., Bergman, E., Mortezanejad, G., and Talebian, M., 2012, Relocation of the 2006 Mw 6.1 Silakhour, Iran, earthquake sequence: details of fault segmentation on the main recent fault: Bulletin of the Seismological Society of America, 102, 398–416.
Hanks, T. C., and Kanamori, H., 1979, A moment magnitude scale: Journal of Geophysical Research, 84(2), 2348–2350.
Herrmann, R. B., and Kijko, A., 1983, Modeling some empirical vertical component Lg relations: Bulletin of the Seismological Society of America, 73, 157-171.
Hwang, R. D., Wang, J. H., Huang, B. S., Chen, K. C., Huang, W. G., Chang, T. M., Chiu, H. C., and Tsai, C. P., 2001, Estimates of stress drop of the Chi-Chi, Taiwan, earthquake of 20 September 1999 from near-field seismograms: Bulletin of the Seismological Society of America, 91, 1158-1166.
Kanamori, H., 1978. Quantification of Earthquakes, Nature 271, 411-414,  doi:10.1038/271411a0.
Kanamori, H., 1977, The energy release in great earthquakes: Journal of Geophysical Research, 82, 1981–1987.
Madariaga, R., 1976, Dynamics of an expanding circular fault: Bulletin of the Seismological Society of America, 66, 639-666.
Nelder, J. A., and Mead, R., 1965, A simplex method for function minimization: Computer Journal, 7, 308–313, doi:10.1093/comjnl/7.4.308.
Shoja-Taheri, J., Naserieh, D., and, Ghofrani, H., 2007, ML and Mw scales in the Iranian Plateau based on the strong motion records: Bulletin of the Seismological Society of America., 97(2), 661–669, doi: 10.1785/0120060132
Iranian Journal of Geophysics
Volume 12, Issue 4
March 2019
Pages 157-171

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