Stress Field Inversion Analysis of Earthquake Focal Mechanisms in Northwestern Iran: Implications for Tectonic Regimes
- سال انتشار: 1402
- محل انتشار: مجله فیزیک زمین و فضا، دوره: 49، شماره: 4
- کد COI اختصاصی: JR_JESPHYS-49-4_009
- زبان مقاله: فارسی
- تعداد مشاهده: 51
نویسندگان
Department of Geodesy, Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.
Department of Surveying, Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran.
Department of Geodesy, Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.
چکیده
Understanding the stress field is crucial for assessing seismic risks in Northwestern Iran, a region known for its high seismic activity and geological volatility. The intricate tectonic arrangements involving the Arabian, Anatolian and Eurasian plates contribute to the unstable nature of the area. This study focuses on deducing stress regimes through stress inversion analysis of earthquake focal mechanisms in the North Tabriz Fault system. Analyzing the stress field is essential for understanding the elastic characteristics and geodynamics of the region. This study considers the stress field surrounding the Tabriz Fault, aiming to determine stress parameters and principal stress orientations using focal mechanisms. By analyzing ۳۵ earthquake focal mechanism datasets from the Global Centered Moment Tensor and the Iranian Seismological Center, stress field inversions were conducted using Michael's linear inversion method and the iterative joint inversion method. The two techniques yielded distinct outcomes, with the iterative joint inversion method proving more accurate in determining stress fields and principal stress orientations. The Plunge values of and were observed to be relatively insignificant, measuring ۳.۲۴ and ۲.۰۶, respectively. A value close to ۹۰ degrees, specifically ۸۶.۱۴, was determined for . The trend values for and were found to be ۱۴۶.۰۸ and ۵۵.۹۷, respectively, while exhibited a trend value of ۲۹۳.۵۱. To estimate the orientation of the maximum horizontal stress (SH), the iterative joint inversion method was employed, yielding an estimation of . The trend and plunge calculated from this method for , and were also utilized in this estimation. The findings indicate the existence of strike-slip faults in proximity to the North Tabriz Fault. The stress direction observed and the trajectory of the fault system suggest the influence of a transpressional mechanism. The predominant right-lateral strike-slip motion observed aligns with the prevailing tectonic regime in the region, providing evidence of strike-slip and thrust faulting stress regimes. The results contribute to a better understanding of the stress field and geodynamic situation in Northwestern Iran. They provide valuable insights for spatial analysis of future earthquakes and assessing seismic hazards in the region.کلیدواژه ها
Stress filed, Focal mechanism, Stress inversion, Horizontal stress (SH), North Tabriz Fault (NTF)اطلاعات بیشتر در مورد COI
COI مخفف عبارت CIVILICA Object Identifier به معنی شناسه سیویلیکا برای اسناد است. COI کدی است که مطابق محل انتشار، به مقالات کنفرانسها و ژورنالهای داخل کشور به هنگام نمایه سازی بر روی پایگاه استنادی سیویلیکا اختصاص می یابد.
کد COI به مفهوم کد ملی اسناد نمایه شده در سیویلیکا است و کدی یکتا و ثابت است و به همین دلیل همواره قابلیت استناد و پیگیری دارد.