Earthquakes in Iran

Shortly after midnight on June 20, 1990, a magnitude 7.4 earthquake struck the provinces of Gilan and Zanjan in northwestern Iran, devastating the cities of Manjil, Rudbar, and Lushan and killing approximately 40,000 people. The earthquake struck while most of the population was asleep, and the widespread use of unreinforced masonry and adobe construction meant that buildings collapsed instantly, trapping tens of thousands beneath the rubble. Over 60,000 people were injured, 500,000 were left homeless, and the destruction extended across an area of roughly 10,000 square kilometers.

The earthquake ruptured along the Rudbar Fault in the Alborz mountain range, an area where the compressive stresses of the Arabian-Eurasian collision are accommodated by thrust and strike-slip faulting. Massive landslides triggered by the shaking buried entire villages in the steep mountain terrain, and many remote communities were cut off from rescue efforts for days as roads were blocked by debris. The destruction of the agricultural infrastructure in the affected region caused economic hardship that persisted for years after the earthquake.

The Manjil-Rudbar earthquake was a stark demonstration of the lethal intersection between Iranian seismicity and Iranian construction practices. International rescue teams that arrived in the aftermath noted that the mortality rate was almost entirely attributable to building collapse, not to secondary hazards like fire or tsunami. The disaster prompted renewed efforts to improve building codes in Iran, though enforcement remained inconsistent, particularly in rural areas. The earthquake also highlighted the critical importance of construction timing: striking at night, when people were inside their most vulnerable structures, the earthquake's death toll was far higher than it would have been during daytime hours.

At 5:26 in the morning on December 26, 2003, a magnitude 6.6 earthquake struck the ancient city of Bam in southeastern Iran, killing approximately 26,271 people and injuring over 30,000. The earthquake was relatively moderate in magnitude, but its epicenter was located directly beneath the city, and the shallow depth of the rupture produced extremely intense shaking. Over 85 percent of Bam's buildings collapsed, including the historic Arg-e Bam, a UNESCO World Heritage Site and one of the largest adobe structures in the world, which had stood for over 2,000 years.

The destruction of Bam was a human catastrophe of enormous proportions for a city of roughly 100,000 people. The earthquake struck on a Friday morning, the Islamic day of rest, when nearly the entire population was at home and asleep. Bam's buildings were overwhelmingly constructed of unreinforced adobe and mud brick, materials that are extremely heavy and brittle, offering virtually no resistance to strong ground shaking. Rescue efforts were hampered by the completeness of the destruction: with so few structures left standing, there were no landmarks to guide searchers, and heavy equipment was needed to move the massive adobe debris.

The Bam earthquake drew worldwide attention and an unprecedented international relief response. It became a symbol of the devastating consequences of building with vulnerable materials in earthquake-prone regions. The disaster prompted Iran to accelerate its efforts to replace adobe construction with reinforced concrete and steel, though the scale of the challenge remains immense. The painstaking restoration of Arg-e Bam, ongoing to this day, stands as both a monument to what was lost and a commitment to preserving cultural heritage in the face of natural hazards.

On the evening of November 12, 2017, a magnitude 7.3 earthquake struck the Iran-Iraq border region near the city of Sarpol-e Zahab in Kermanshah Province. The earthquake killed over 630 people in Iran and at least 9 in Iraq, with more than 8,000 injured. The shaking was felt across a vast area from Tehran to Baghdad, and the earthquake was the largest to strike the Zagros fold-and-thrust belt in decades. The city of Sarpol-e Zahab suffered extensive damage, with many newer reinforced concrete buildings collapsing alongside older masonry structures.

The earthquake occurred at an intermediate depth of about 19 kilometers on a blind thrust fault within the Zagros Mountains, where the Arabian Plate's northward movement is absorbed by folding and faulting. The collapse of a large government-built housing complex called Mehr Housing in Sarpol-e Zahab drew particular attention, as these relatively modern buildings had been constructed under a national affordable housing program and were expected to perform well in earthquakes. Their failure raised serious questions about construction quality and code enforcement in Iran's public housing programs.

The Sarpol-e Zahab earthquake underscored a painful reality: even in areas where Iran has attempted to modernize its building stock, the gap between code requirements and actual construction quality can prove fatal. The event led to public outcry over construction standards and renewed calls for stronger enforcement mechanisms. It also demonstrated the ongoing seismic hazard posed by the Zagros Mountains, where the Arabian-Eurasian collision continues to build stress on faults capable of generating major earthquakes near population centers on both sides of the Iran-Iraq border.

On September 16, 1978, a magnitude 7.4 earthquake devastated the remote desert town of Tabas in eastern Iran, killing approximately 15,000 of the town's 17,000 residents. The mortality rate of nearly 85 percent was among the highest ever recorded for an earthquake-affected community, a consequence of the total collapse of virtually every building in the town. Tabas was constructed almost entirely of unreinforced adobe, a traditional material well-suited to the extreme desert climate but catastrophically vulnerable to seismic shaking.

The earthquake ruptured along a thrust fault in the Shotori Mountains of eastern Iran, producing surface ruptures over 85 kilometers long with vertical displacements of up to three meters. The isolation of Tabas, located in the middle of the Dasht-e Lut desert, delayed rescue operations significantly. When aid workers finally reached the town, they found scenes of almost total destruction: buildings had been reduced to mounds of earth, and the few survivors were struggling without water, food, or medical supplies in the punishing desert heat.

The Tabas earthquake occurred during a period of intense political upheaval in Iran, just months before the Islamic Revolution, and the government's response to the disaster became entangled with broader political tensions. Despite the difficult circumstances, the earthquake generated important scientific data about reverse faulting in the Iranian plateau and highlighted the extreme vulnerability of adobe communities. The near-total destruction of Tabas became a reference point for earthquake engineers studying the performance of traditional construction in strong shaking, and the rebuilt town was constructed with modern materials and seismic design principles.

On September 1, 1962, a magnitude 7.1 earthquake struck the Buin Zahra district of Qazvin Province, roughly 100 kilometers west of Tehran. The earthquake killed approximately 12,225 people and destroyed over 21,000 homes across more than 300 villages. The region's construction was dominated by heavy mud-brick and stone buildings with thick earthen roofs, structures designed to insulate against extreme temperatures but which collapsed with lethal force during the earthquake. Entire villages were flattened, leaving barely a wall standing.

The earthquake ruptured along the Ipak Fault, producing a surface rupture approximately 100 kilometers long across the agricultural plains west of Tehran. The proximity of the affected area to the capital made this earthquake particularly significant for Iranian authorities, as it demonstrated that devastating earthquakes could strike within easy reach of Tehran's millions. The disaster prompted one of Iran's first serious efforts to develop earthquake-resistant building guidelines, though implementation remained limited for decades.

The Buin Zahra earthquake holds a somber place in Iran's seismic history as one of many events that illustrated the deadly pattern of vulnerable construction in a highly seismic country. The lessons from 1962 were echoed repeatedly in subsequent disasters at Tabas, Manjil, and Bam, each time highlighting the same fundamental problem: Iran's traditional building materials are poorly suited to the seismic forces that regularly affect the country. The earthquake remains a cautionary example of how proximity to fault lines, combined with inadequate construction, creates conditions for catastrophic loss of life.