Interpretations of ground motion records from the 2017 Mw 7.3 Ezgeleh earthquake in Iran
- 82 Downloads
This study examines the time and frequency features of strong motion records obtained during the 12th November 2017 Mw 7.3 Ezgeleh (Iran) Earthquake. Different parameters including peak ground acceleration (PGA), peak ground velocity (PGV), spectral acceleration, significant duration, Arias intensity and Fourier amplitude are illustrated to provide a clear view on main characteristics of this event. As an important finding, a broad-band frequency content characteristic is obvious from the analysis of Fourier amplitude spectra obtained at four closest stations records. According to the results, the record obtained at Sarpol-e Zahab station could be considered as near-fault pulse-like motion. The amount of input energy and its corresponding level of frequency are discussed based on wavelet analysis. Results showed that more than 50% of earthquake energy at Sarpol-e Zahab city has been concentrated around 0.45 s which is close to the natural vibration period of low-to mid rise structures in the region. Finally, seismic intensity in terms of modified Mercalli intensity was extracted based on the Fourier spectrum amplitude and the peak ground motion parameters (PGA, PGV) in Sarpol-e Zahab city which was the worst affected area.
KeywordsGround motion records Time–frequency features Wavelet analysis Zagros Ezgeleh earthquake
The authors gratefully acknowledge the contributions by Building and Housing Research Center (BHRC) for providing the strong-motion records used in this study. The author gratefully acknowledges the contributions by Dr. M.P Shahvar who facilitate data preparation from BHRC. The authors are grateful to the authoritative reviewers and Dr. John Douglas whose comments significantly improved quality of this study.
- Berberian M (1995) Master “blind” thrust faults hidden under Zagros folds: active basement tectonics and surface morphotectonics. Techtonophysics 89:120–139Google Scholar
- Chang Z, Sun X, Zhai C, Zhao JX, Xie L (2017) An improved energy-based approach for selecting pulse-like ground motions. Earthquake Eng Struct Dynam 45(3):757–771Google Scholar
- Iran Strong Motion Network, Building & Housing Research Center (BHRC)Google Scholar
- Irikura K, Kamaei K (1994) Estimation of strong ground motion in broad-frequency band based on a seismic source scaling model and an empirical Green’s function technique. Ann Geofis 37:1721–1743Google Scholar
- Minimum Design Loads for Buildings and Other Structures (ASCE 7-10) (2010) American Society of Civil Engineers, Reston, VirginiaGoogle Scholar
- Nakamura Y (1989) A method for dynamic characteristics estimation of subsurface using micro-tremor on the ground surface. Quarterly report of RTRI 30, pp 25–33, Railway Technical Research Institute, Tokyo, JapanGoogle Scholar
- Preliminary report on 12th November 2017, magnitude 7.3 earthquake in Sarpol-e Zahab, Kermanshah Province, 3rd Edition, November 2017, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran (in Persian) Google Scholar
- Standard No. 2800 (2014) Iranian code of practice for seismic resistant design of buildings, 3. Building & Housing Research Center, Iran (in Persian) Google Scholar
- Zhai C, Cahng Z, Li SH, Chen Z, Xie L (2013) Quantification of near-fault pulse-like ground motion based on energy. Bull Earthq Eng 103(5):2591–2603Google Scholar