بررسی ویژگی های دینامیکی و سینماتیکی زمین لرزه 12 نوامبر 2017 سرپل ذهاب در استان کرمانشاه

نوع مقاله : Articles

نویسندگان

پژوهشکده زلزله شناسی، پژوهشگاه بین‌المللی زلزله‌شناسی و مهندسی زلزله، تهران، ایران

چکیده

زمین‌لرزه 12 نوامبر 2017 که در مرز شمالی عراق و غرب ایران (MW = 7.3) به وقوع پیوست، تنها زمین‌لرزه‌ی دستگاهی است که با بزرگای بیش از 7 در ناحیه شمال غربی زون تراستی زاگرس (ZTZ) ثبت گردیده است. نزدیک‌ترین شهر به کانون زمین‌لرزه، شهر ازگله با فاصله تقریبی  5 کیلومتر می‌باشد. همچنین عمق زمین‌لرزه حدود 11 کیلومتر گزارش شده است. این زمین‌لرزه موجب کشته شدن صدها نفر و مجروح شدن هزاران نفر گردیده و خسارات اقتصادی زیادی را در استان کرمانشاه به همراه داشته است. در این مطالعه با استفاده از اطلاعات لرزه‌ای دورلرز ثبت شده در شبکه لرزه‌ای جهانی (GDSN) ، گشتاور لرزه‌ای این زمین‌لرزه با استفاده از روش کیلیس-  بورک (1960)  (Keilis-Borok) محاسبه و مقدار متوسط آن برابر 1.45E+27 دین- سانتی‌متر تعیین گردیده است. با توجه به تابع زمانی چشمه و به دست آوردن اوج تابع زمان چشمه (δt1= 1.935) و گستره زمانی که بیشترین شکستگی طی آن ایجاد می‌شود (𝛿𝑡2= 3.225) و زمان شروع افت شکستگی بر روی سطح گسل (𝛿𝑡3= 1.612)، مدت‌زمان گسیختگی این زمین‌لرزه4.998  ثانیه تعیین گردیده است.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation of Dynamic and Kinematic Parameters of November 12, 2017 Sarpol-e Zahab Earthquake in Zagros Region

نویسندگان [English]

  • Nahid Aghmioni Khodi
  • Mehdad Mostafazadeh
Seismology Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
چکیده [English]

The Zagros fold Thrust belt is approximately 1,500 to 1,600 km long and 200 to 300 km wide, formed from western Iran to the Strait of Hormuz under the influence of the convergence of the Arabian and Eurasian plateaus. The faults in this belt are mainly parallel to the folds and are of the thrust type with slopes to the north to the northeast. The Zagros zone is divided into five units based on morpho-tectonic, seismic, and structural data, and it is separated by deep faults called the High Zagros Fault (HZF), Mountain Front Fault (MFF), Zagros Foredeep Fault (ZFF), Main Zagros Reverse Fault (MZRF) and Kazerun Fault (KF). The earthquake of November 12, 2017, which occurred in the Zagros region near to Iran-Iraq border (MW = 7.3), is the only earthquake with a magnitude of more than 7 recorded in the northwestern part of the Zagros Thrust Zone (ZTZ). The largest earthquake in the region near the source of the recent earthquake was the January 11, 1967 earthquake (M = 6.1), located about 100 km south of the epicenter of the 2017 earthquake. The closest city to the epicenter of the recent earthquake is the city of Azgeleh with a distance of approximately 5 km. The depth of the earthquake was also reported to be about 11 km. In this study, using seismic data recorded in the Global Digital Seismic Network (GDSN), the seismic moment of this earthquake was calculated using the Kelis-Borok method and its average value obtained was 1.45E+27 dyne-cm. According to the source time function of this earthquake and obtaining the peak value of the rise time, duration of the most fracturing and fall time, the total rupture time is calculated that is 4.998 seconds.

کلیدواژه‌ها [English]

  • Source Time Function
  • Seismic Moment
  • Sarpol-e Zahab
  • Zagros
1.    Berberian, M. (1976) Contribution to the Seismo-tectonics of Iran (part II). Report No. 39, Geological Survey of Iran.
2.    Nabavi, M.S. (1977) Aspects of Seismic Behavior of Iran, Especially the Zagros Area. Ph.D. Thesis, University London, London, 227p.
3.    Stocklin, J. (1968a) Structural history and tectonics of Iran: a review. American Association of Petroleum Geologists Bulletin, 52, 1229-1258.
4.    Berberian, M. (1995) Master blind thrust faults hidden under the Zagros folds: active basement tectonics and surface morphotectonics. Tectono-physics, 241, 193-224.
5.    Aghanabati, S.A. (2005) Geological of Iran. Geological Survey of Iran, Ministry of Industries and Mines, Tehran, 45p. (In Persian).
6.    Brune, J.N. (1971) Correction (to Brune, 1970). Journal of Geophys. Res., 76, 5002.
7.    Aki, K. (1967) Scaling Law of Seismic Spectrum. Journal of Geophy. Res., 72(4).
8.    Haskell, N. (1966) Total  energy  and  energy  spectral density of  elastic wave  radiation  from  propagating faults, 2, A  statistical source  model. Bull. Seism. Soc. Am., 56, 125-140.
9.    Hanks, T.C. and Wyss, M. (1972) The use of body- wave spectra in the determination of seismic source parameters. Bull. Seism. Soc. Am., 62, 561-589.
10.    Keilis-Borok, V.I. (1960) Investigation of the mechanism of earthquakes. Sov. Res. Geophys. (English Transl.) 4, 29.
11.    McCaffery, R., Abers, G., and Zwick, P. (1991) 'Inversion of teleseismic body waves'. In: Digital Seismogram Analysis and Waveform Inversion   (Ed. By W.H.K. Lee), IASPEI Software Library,    3, 81-166.
12.    Langston, C.A. and Helmberger, D.V. (1975) A procedure for modeling shallow dislocation sources. Geophys. J. Roy. Astr. Soc., 42, 117-130.
13.    Archuleta, R.J., Cranswick, E., Mueller, C., and Spudich (1982) Source Parameters of the 1980 Mammuth Lakes, California, Earthquake Sequence. Journal of Geophysical Risearch, 87, 4595-4607.
14.    Chung, W.Y. and Kanamori, H. (1980) Variations of seismic source parameters and stress drops within a descending slab and its implications in plate mechanics. Phys. Earth Planet. Inter., 23, 134-159.
15.    Husebye, E.S. and Mykkeltveit, S. (1980) Identifi-cation of Seismic Sources Earthquake or Underground Explosion. Proceeding of the NATO Advanced study Institute Held at Voksenasen, Oslo, Norway, 72-97.