پهنه‌بندی لرزه‌ای استان گلستان

The study area includes golestan province and is located in the north and north-east of iran. this area contains gonbad, koh-‎e-kurkhod and a part of gorgan quadrangle maps. the aims of this research are as follows: detailed seismicity and ‎seismotectonic studies, recognition of active faults and preparing seismic hazard zoning map based on peak ground ‎accelerations (pga) for difference return periods. these studies performed in order to seismic resistance of important ‎buildings, reducing of human and economy disaster against earthquake hazards and future planning for golestan province. ‎this area is located in the central iran and kopeh-dagh seismotectonic provinces. there are many active faults within this area ‎and many destructive earthquakes occurred along them. for example the atrak-nesa earthquake of august 943 with ms 7.4 ‎occurred due to activity of ashkhaneh fault (eastern segment of takal kuh). many other active faults such as khazar, ali-‎abad, gomishan, maraveh-tappeh etc distinguished in this area so that this province can be affected of reactivation of them. ‎seismic zoning maps prepared base on peak ground acceleration for return periods of 475 and 2475 years. the results show the ‎golestan province is divided to four seismic zones as follows:the area with pga more than 0.35g that named very high ‎seismic zone includes parts of south of province; the area with pga between 0.3 g to 0.35g that named high seismic zone ‎includes southern, eastern and north-eastern parts of province; the area with pga between 0.25g to 0.3g that named moderate ‎seismic zone; the area with pga less than 0.25g that named low seismic zone mainly includes western and north-western ‎parts of province.‎