Geometric Approach for Identifying Activated Fault Planes; Case Study: the 2014 Murmuri Earthquake, Northwestern Zagros, Iran

نوع مقاله : مقاله پژوهشی

نویسندگان

1 Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran.

2 Department of Earth and Planetary Science, Rutgers, The State University of New Jersey, New Jersey, US.

چکیده

An analysis was conducted on the 2014 Murmuri earthquake sequence in the Zagros Mountains of Iran, aiming to determine the main fault plane. The sequence comprised of an initial Mw 6.2 earthquake, followed by five aftershocks with magnitudes exceeding 5.4. Events were relocated to enhance understanding of the hypocenter uncertainties. The primary earthquake, registering a magnitude of Mw 6.2, was followed by a sequence of events with Mw>5 within 24 hours of the main shock. To identify the earthquake’s source parameters, three components—local waveforms reported by the broadband networks of the Iranian Seismological Center (IRSC), the International Institute of Earthquake Engineering and Seismology (IIEES), and the Iraqi Seismological Network (ISN) were utilized. The analysis was conducted using the ISOLA software, employing a multiple-point source representation and the iterative deconvolution method. The events were relocated using the HYPOINVERSE code to ensure highly accurate results. The stations provided comprehensive coverage, contributing to the high reliability of the results. The method employed in the paper is the H-C method. This simple and readily applicable technique proves highly effective when precise information on the event location and its Centroid Moment Tensor (CMT) solution is available. The findings indicate that the Mountain Front Fault (MFF) can be identified as the causative fault plane of the event.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Geometric Approach for Identifying Activated Fault Planes; Case Study: the 2014 Murmuri Earthquake, Northwestern Zagros, Iran

نویسندگان [English]

  • Maryam Abbasian 1 2
  • Mehdi Rezapour 1
1 Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran.
2 Department of Earth and Planetary Science, Rutgers, The State University of New Jersey, New Jersey, US.
چکیده [English]

An analysis was conducted on the 2014 Murmuri earthquake sequence in the Zagros Mountains of Iran, aiming to determine the main fault plane. The sequence comprised of an initial Mw 6.2 earthquake, followed by five aftershocks with magnitudes exceeding 5.4. Events were relocated to enhance understanding of the hypocenter uncertainties. The primary earthquake, registering a magnitude of Mw 6.2, was followed by a sequence of events with Mw>5 within 24 hours of the main shock. To identify the earthquake’s source parameters, three components—local waveforms reported by the broadband networks of the Iranian Seismological Center (IRSC), the International Institute of Earthquake Engineering and Seismology (IIEES), and the Iraqi Seismological Network (ISN) were utilized. The analysis was conducted using the ISOLA software, employing a multiple-point source representation and the iterative deconvolution method. The events were relocated using the HYPOINVERSE code to ensure highly accurate results. The stations provided comprehensive coverage, contributing to the high reliability of the results. The method employed in the paper is the H-C method. This simple and readily applicable technique proves highly effective when precise information on the event location and its Centroid Moment Tensor (CMT) solution is available. The findings indicate that the Mountain Front Fault (MFF) can be identified as the causative fault plane of the event.

کلیدواژه‌ها [English]

  • Moment Tensor
  • Murmuri
  • Fault Plane
  • H-C Method
  • ISOLA

مراجع

Alavi, M. (2004). Regional stratigraphy of the Zagros fold-thrust belt of Iran and its proforeland evolution. American journal of Science, 304(1), 1-20.
Baker, C., Jackson, J., & Priestley, K. (1993). Earthquakes on the Kazerun Line in the Zagros Mountains of Iran: strike-slip faulting within a fold-and-thrust belt. Geophysical Journal International, 115(1), 41-61.
Berberian, M. (1976). Contribution to the seismotectonics of Iran (part II-III): In commemoration of the 50th anniversary of the Pahlavi dynasty (No. 40). Ministry of Industry and Mines, Geological Survey of Iran, Tectonic and Seismotectonic Section.
Berberian, M. (1995). Master “blind” thrust faults hidden under the Zagros folds: active basement tectonics and surface morphotectonics. Tectonophysics, 241(3-4), 193-224.
Copley, A., Karasozen, E., Oveisi, B., Elliott, J.R., Samsonov, S., & Nissen, E. (2015). Seismogenic faulting of the sedimentary sequence and laterally variable material properties in the Zagros Mountains (Iran) revealed by the August 2014 Murmuri (E. Dehloran) earthquake sequence. Geophysical journal international, 203(2), 1436-1459.
DeMets, C., Gordon, R.G., Argus, D.F., & Stein, S. (1990). Current plate motions. Geophysical journal international, 101(2), 425-478.
Delouis, B., & Legrand, D. (1999). Focal mechanism determination and identification of the fault plane of earthquakes using only one or two near-source seismic recordings. Bulletin of the Seismological Society of America, 89(6), 1558-1574.
Hardebeck, J.L., & Hauksson, E. (2001). Stress orientations obtained from earthquake focal mechanisms: What are appropriate uncertainty estimates?. Bulletin of the Seismological Society of America, 91(2), 250-262.
Hatzfeld, D., Tatar, M., Priestley, K., & Ghafory-Ashtiany, M. (2003). Seismological constraints on the crustal structure beneath the Zagros Mountain belt (Iran). Geophysical Journal International, 155(2), 403-410.
Havskov, J., & Ottemöller, L. (2005). SEISAN Version 8.1-introductory training course. Norway: Bergen University.
Hessami, K., Pantosti, D., Tabassi, H., Shabanian, E., Abbassi, M.R., Feghhi, K., & Solaymani, S. (2003). Paleoearthquakes and slip rates of the North Tabriz Fault, NW Iran: preliminary results. Annals of Geophysics, 46(5), 903-915.
Jackson, J. (1980). Errors in focal depth determination and the depth of seismicity in Iran and Turkey. Geophysical Journal International, 61(2), 285-301.
Jackson, J., & Fitch, T. (1981). Basement faulting and the focal depths of the larger earthquakes in the Zagros mountains (Iran). Geophysical Journal International, 64(3), 561-586.
Jackson, J., & McKenzie, D. (1984). Rotational mechanisms of active deformation in Greece and Iran. Geological Society, London, Special Publications, 17(1), 743-754.
Kikuchi, M., & Kanamori, H. (1991). Inversion of complex body waves—III. Bulletin of the Seismological Society of America, 81(6), pp.2335-2350.
Klein, F.W. (1984). User's guide to hypocenters, a program for Vax and Pc 350 computers to solve for earthquake locations. US Geol. Surv. Open-File Rept, pp.84-000.
Maggi, A., Jackson, J.A., Priestley, K., & Baker, C. (2000). A re‐assessment of focal depth distributions in southern Iran, the Tien Shan and northern India: Do earthquakes really occur in the continental mantle?. Geophysical Journal International, 143(3), 629-661.
McClusky, S., Reilinger, R., Mahmoud, S., Ben Sari, D., & Tealeb, A. (2003). GPS constraints on Africa (Nubia) and Arabia plate motions. Geophysical Journal International, 155(1), 126-138.
Motagh, M., Bahroudi, A., Haghighi, M.H., Samsonov, S., Fielding, E., & Wetzel, H.U., 2015. The 18 August 2014 M w 6.2 Mormori, Iran, earthquake: A thin‐skinned faulting in the Zagros Mountain inferred from InSAR measurements. Seismological Research Letters, 86(3), 775-782.
Ni, J., & Barazangi, M. (1986). Seismotectonics of the Zagros continental collision zone and a comparison with the Himalayas. Journal of Geophysical Research: Solid Earth, 91(B8), 8205-8218.
Rezapour, M., & Mottaghi, A.A. (2018). The 18 August 2014 Mw 6.2 Murmuri, Southwest Iran, Earthquake: Aftershock Sequence Analysis. Bulletin of the Seismological Society of America, 108(4), 1905-1917.
Sepehr, M., & Cosgrove, J.W. (2005). Role of the Kazerun Fault Zone in the formation and deformation of the Zagros Fold‐Thrust Belt, Iran. Tectonics, 24(5), 1-15.
Sokos, E.N., & Zahradnik, J. (2008). ISOLA a Fortran code and a Matlab GUI to perform multiple-point source inversion of seismic data. Computers & Geosciences, 34(8), 967-977.
Vernant, P., Nilforoushan, F., Hatzfeld, D., Abbassi, M.R., Vigny, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, A., Bayer, R., & Tavakoli, F. (2004). Present-day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and northern Oman. Geophysical Journal International, 157(1), 381-398.
Walker, R., & Jackson, J. (2002). Offset and evolution of the Gowk fault, SE Iran: a major intra-continental strike-slip system. Journal of structural Geology, 24(11), 1677-1698.
Zahradnik, J., Gallovic, F., Sokos, E., Serpetsidaki, A., & Tselentis, A. (2008). Quick fault-plane identification by a geometrical method: Application to the Mw 6.2 Leonidio earthquake, 6 January 2008, Greece. Seismological Research Letters, 79(5), 653-662.
Zamani, A., & Agh-Atabai, M. (2009). Temporal characteristics of seismicity in the Alborz and Zagros regions of Iran, using a multifractal approach. Journal of Geodynamics, 47(5), 271-279.
فیزیک زمین و فضا
دوره 50، شماره 4
تاریخ انتشار الکترونیکی: 25 اسفند 1403
اسفند 1403
صفحه 125-136

فایل ها

هم رسانی

ارجاع به این مقاله

آمار