The megacity of Tehran, the capital of Iran, is subjected to a high earthquake risk. Located at the central part of the Alpine–Himalayan seismic belt, Tehran is surrounded by several active faults that show some M7+ historical earthquake records. The high seismic hazard in combination with a dense population distribution and several vulnerability factors mean Tehran is one of the top 20 worldwide megacities at a high earthquake risk. This article aims to prepare an assessment of the present-day earthquake risk in Tehran. First, the earthquake risk components including hazard, exposure, and vulnerability are evaluated based on some accessible GIS-based datasets (e.g., seismicity, geology, active faults, population distribution, land use, urban fabric, buildings’ height and occupancy, structure types, and ages, as well as the vicinity to some critical infrastructures). Then, earthquake hazard maps in terms of PGA are prepared using a probabilistic approach as well as a surface rupture width map. Exposure and vulnerability maps are also provided deterministically in terms of population density and hybrid physical vulnerability, respectively. Finally, all these components are combined in a spatial framework and an earthquake risk map is provided for Tehran.

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cracks triggered by the earthquake. Coulomb stress changes on the source fault 71 indicating consistency between aftershock distribution and high loaded stress 72 zones. Based on the stress change on neighbouring active faults around this area, 73 the Kermanshah Earthquake has brought two segments of the Zagros Mountain 74Front Fault (MFF), MFF-1 and MFF-2, 0.5-3.1MPa and 0.5-1.96MPa closer to 75 failure respectively, suggesting the risk of future earthquakes. Recent major 76 aftershocks (M W ≥5.0) could probably ease the seismic hazard on MFF-2, but the 77 risk of earthquakes on MFF-2 is still increasing.

Introduction: Earthquake is the most important cause of death from natural disasters in Iran. This paper brings attention to the main causes of loss of life due to the Kermanshah province earthquake (Nov 12 2017), and provides a wakeup call about the unsafe nature of buildings there. Methods: This study is based on official reports review and a field assessment in the areas affected by the earthquake in western Iran. Results: Although buildings in this area are mainly old structures, strangely, more than 70% of the destroyed buildings in this earthquake were under 5 years of age, newly built or renovated buildings according to mandated building codes. Discussion: Mandated building codes and construction rules and regulations are not respected even for the newly constructed or reconstructed structures buildings. Keywords: Earthquake, Iran, construct, reconstruct, Building codes