TY - JOUR ID - 131130 TI - Seismotectonics of the East Alborz and Kopeh- Dagh zones using local seismic network data JO - Scientific Quarterly Journal of Geosciences JA - GSJ LA - en SN - 1023-7429 AU - Kouhpeyma, M. AU - Talebian, M. AU - Chen, L. AU - Ghods, A. AU - Ghorashi, M. AD - Ph.D. Student, Research Institute for Earth Sciences, Geological survey of Iran, Tehran, Iran AD - Associate Professor, Research Institute for Earth Sciences, Geological survey of Iran, Tehran, Iran AD - Professor, Institute of Geology and Geophysics, Chinese Academy of Science, Beijing, China AD - Associate Professor, Department of Earth Sciences, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran AD - Associate Professor, Department of Geology, Science and Research Branch, Islamic Azad university, Tehran, Iran Y1 - 2021 PY - 2021 VL - 31 IS - 1 SP - 199 EP - 208 KW - Seismotectonic KW - focal mechanism KW - Kopeh Dagh KW - Binalud KW - Iran DO - 10.22071/gsj.2021.131130 N2 - The Kopeh Dagh and Binalud-Alla Dagh mountains are important structural elements located in the northeastern boundary of Arabia-Eurasia collision zone. Due to existence of large cities with a long history of civilization, there is a relatively rich body of data on historical seismicity in this area. Nonetheless, little adequate instrumental seismic data were available prior to this study. In this paper, we utilized the temporary China-Iran local seismic network data deployed in the area for 13 months. Based on this data, we determined 37 focal solutions through first motion polarity approach suggesting a combination of strike-slip, reverse and normal mechanisms. There is a significant concentration of epicenters and focal mechanisms around the eastern Alborz - Kopeh Dagh boundary along the Atrak River. The southern and western boundaries of the Binalud Mountains also show relatively high seismic activities. The Local magnitude (ML) of the events ranges from 3.5 to 4.9 with depths of up to 20 km, mostly concentrated at ~10 km. The principal stress axes and slip vectors obtained from the focal mechanisms agree well with kinematic state of main faults and tectonic regime of the area, confirming the seismogenic nature of these faults. In addition, they are consistent with right-lateral component of slip along thrust faults in eastern Kopeh Dagh and Binalud and both laft- and right-lateral motions in the central Kopeh Dagh. UR - http://www.gsjournal.ir/article_131130.html L1 - http://www.gsjournal.ir/article_131130_e8f19f0691e9b9b50924066a2d1a727a.pdf ER -