Identification of 'Large and Hidden Faults' Within Tehran

The Geological and Mineral Exploration Organization of Iran announced the identification of 'large and hidden faults in the city of Tehran' and stated that, based on new findings, 'the entire city is at risk of earthquakes.' According to Tasnim News Agency, Morteza Talebian, head of the Earth Sciences Research Institute of the Geological and Mineral Exploration Organization of Iran, explained on Tuesday, July 21, that 'all previous risk assessment studies conducted in Tehran were based on the known faults in the north and south of the city, and the role of faults within the city had received less attention.' Until now, the northern fault in the Tajrish area, the northern and southern faults of Shahr-e Rey, and the Kahrizak fault in southern Tehran were considered the most important faults in the Tehran area. However, the head of the Earth Sciences Research Institute announced on Tuesday that 'for the first time in recent studies, large and hidden faults in Tehran have been identified using quantitative measurement methods,' stating: 'The most significant of these is the Pardisan fault in the central part of the city. This hidden fault has a movement rate at least three times that of the northern fault and could pose a significantly greater danger than that fault, comparable to the earthquake that occurred in Bam.' Morteza Talebian also added: 'The earthquake risk in Tehran is not limited to the faults within and on the outskirts of the city; faults located not far from Tehran, including those in the Central Alborz region, can also be hazardous, as evidenced by the Firuzabad-Kajor earthquake, which was felt in Tehran.' He continued: 'Major cities in Iran, including Mashhad and Tabriz, have similar conditions to Tehran, but the problem in Tehran is the high population density, the abundance of old buildings, and their low resistance, which can significantly increase their vulnerability.' The head of the Earth Sciences Research Institute concluded by noting: 'In a dry land like Iran, most cities are located on or near active faults. Given that faults control water resources, relocating cities to areas less prone to risk is not feasible. Constructing earthquake-resistant buildings is the correct solution to provide at least minimal safety during an earthquake.' Earlier this month, on July 5, Mohammad Shakarchi Zadeh, head of the Housing Research Center, also reported that 'maps of fault zones in Tehran' have been prepared, and based on the results of these studies, 'important and sensitive' buildings should not be constructed on fault zones, and 'restrictions' have been applied to buildings taller than 12 stories. Before him, on May 21, Ali Beitollahi, head of the Seismology Office of the Road, Housing, and Urban Development Research Center of Iran, warned that a magnitude six earthquake could 'destroy most' residential buildings in Tehran's dilapidated areas, adding that such an event would endanger the lives of 'one and a half million' residents of these areas. He stated that the population residing in Tehran's dilapidated areas is officially reported to be 1.2 million, while unofficial estimates suggest it could be 1.5 million. Beitollahi referred to these individuals as the 'night population' of Tehran's dilapidated areas and noted that the 'day and floating population of these areas is much larger.' Recently, Gholamreza Pourheidari, head of the Iranian Scientific Association for Crisis Management, mentioned that 'given the occurrence of earthquakes around Tehran, an earthquake in this city is predictable,' stating that 'we do not have a capable and centralized authority for crisis management.' In this context, the construction of buildings taller than 12 stories in Tehran has been 'prohibited.' In the dilapidated areas of Tehran, the lives of 'one and a half million' people are at risk, and in the event of an earthquake, Tehran 'lacks a centralized crisis management authority.'