Gholamreza Abodolahzadeh - Assistant Professor in civil engineering department of Babol University of Technology
Leila Khanmohammadi - PhD student in civil engineering department of Babol University of Technology
Fatemeh Zahedi Tajrishi

Seismic hazard assessment has been done for Gorgan city in this article. Horizontal Peak Ground Acceleration values (PGA) for earthquakes with return periods of 475 and 2475 years have beencalculated for this region by probabilistic approach of seismic hazard analysis. For this purpose, first, active faults and uniform catalogue of earthquakes in a radius of 150 km around Gorgan have been used. After that, seismicity parameters have been evaluated using the methods in which magnitude uncertaintyand incompleteness of earthquake data are considered. By using three attenuation relationships, seismichazard assessment has been carried out using the SEISRISKIII computer program. Two iso- cceleration maps have been prepared to provide a probabilistic estimate of horizontal Peak Ground Acceleration (PGA) over bedrock for two mentioned hazard levels. Finally, the results have been compared with theseismic macrozonation hazard map of Iran, Standard 2800

seismicity parameters, PGA, attenuation relationship, probabilistic approach, Gorgan