Four large earthquakes measuring 6.3 each and their aftershocks affected Herat Province in western Afghanistan in early October 2023. The first two earthquakes occurred on 7 October at 11:11 AFT and 11:42 AFT near the city of Herat, followed by many aftershocks. On 11 and 15 October, two other magnitude 6.3 earthquakes struck the same area. These earthquakes were associated with thrust faulting. The World Health Organization estimated 1,482 fatalities, 2,100 injuries, 43,400 people affected and 114,000 people requiring humanitarian aid due to the mainshock. The 11, 15 and 28 October earthquakes caused a combined seven deaths and 344 injuries.
The earthquakes struck Afghanistan during an ongoing humanitarian crisis following the Taliban takeover in 2021, and existing aid groups were experiencing a lack of funds prior to the disaster. Some aid agencies including UNICEF and the Red Cross appealed for donations in response to the earthquakes. Many international organizations and countries participated in rescue and relief efforts. Hospitals were overwhelmed by the number of injured and lack of proper equipment. Thousands more were made homeless as the country entered the winter.
Tectonic setting
Afghanistan is situated within the broad and complex zone of collision between the Arabian Plate, the Indian Plate, and the Eurasian Plate. The western part of the country is subdivided into the North Afghan Platform to the north and a series of accreted terranes to the south. The North Afghan Platform has remained relatively tectonically stable since the Variscan Orogeny during the Late Palaeozoic, when it became part of Eurasia. To the south there is a collage of continental fragments and magmatic arcs that have been progressively accreted, particularly in the Mesozoic era. The boundary between these two crustal areas is the major right-lateral strike-slip Harirud (or Herat) Fault, which is far less seismically active than the Chaman Fault that runs through the east of the country. To the north of the Harirud Fault, the near parallel Band-e Turkestan Fault does show signs of recent activity, also in a right-lateral sense.
The seismicity of Afghanistan is attributed to the complex and active tectonic interactions between the Arabian, Eurasian, and Indian plates. Within of the 7 October earthquakes epicenters, there have been seven magnitude 6.0 or greater earthquakes with epicenters in Iran. These include a 7.3 earthquake in May 1997 and a 7.1 earthquake in 1979. In June 2022, eastern Afghanistan was affected by an earthquake that killed over 1,000 people.
Earthquakes
The first event, measuring a magnitude of 6.3, struck at 11:11 AFT (06:41 UTC). A magnitude 5.5 aftershock occurred eight minutes later. Another magnitude 6.3 event struck at 11:42 AFT (07:12 UTC), followed by a magnitude 5.9 aftershock. On 11 October, a third 6.3 earthquake occurred within the same area and another event of the same magnitude occurring on 15 October. The United States Geological Survey said all four earthquakes were the result of shallow thrust faulting. The fault plane solution indicate a rupture source striking east–west with a north or south dip. On 28 October, a 5.0 event hit the area, followed by a 4.8 aftershock the next day.
According to seismologists, these earthquakes had epicenters between the Siakhubulak Fault in the north and Herat Fault in the south. According to satellite data from Sentinel-1A, an area measuring by and extending east–west around the location of these earthquakes was uplifted. Meanwhile, the satellite detected subsidence in a small area east of the uplifted zone. The seismologists added that the ground deformation was diffuse and inferred the earthquakes were associated with a blind thrust fault. The fault responsible is likely a structure located between the Herat and Siakhubulak faults.
Italy's National Institute of Geophysics and Volcanology released two possible finite fault models for the second large earthquake. In both models, no slip occurred at the top depth of the model. The first model is a north-dipping, east-southeast–west-northwest striking thrust fault. The rupture mechanism was reverse-faulting with a small right-lateral component, initiating at a depth of . In this model, the maximum slip was at depth and immediately east of the hypocenter. Slip of or greater was observed east and west of the hypocenter although the largest slip (>) was observed to the east.
In the latter model, the fault dips to the south and strikes east–west. The focal depth is inferred to be ; the zone of maximum slip is located east of the hypocenter, where it peaked at . Overall, to the immediate east and west of the hypocenter, the slip was about although the larger values were observed further away.
Impact
7 October earthquakes The World Health Organization reported 1,482 deaths as of 19 October while Taliban officials said about 1,000 had died. The Taliban revised the death toll on 11 October from a previous estimate of over 3,000. They added that confusion arose as rescue groups had counted twice and there were coordination issues. The World Health Organization said 90 percent of the casualties were women and children who died in their homes when they collapsed. At the time of the earthquakes, most men were outdoors, the organization added. The World Health Organization recorded 2,100 wounded while the Taliban provided an estimate of 2,400 people injured.
The United Nations also estimated 43,300 people affected and 114,000 people in need of aid. Among the villages affected were Mahal Wadakah, where 20 people died, Dasht Hows, Bahadorzai, and Zoryan. Telephone communications were also lost. In addition to the destruction in Herat Province, collapsed houses and injuries were also reported in the neighbouring provinces of Badghis and Farah.
Over 21,500 houses were destroyed, and 17,088 others were severely damaged. At least 21,300 buildings, including 21 health facilities and 21 schools also received damage. Homes constructed of mud constituted the hardest-hit settlements; a resident of one of the affected areas said many homes collapsed during the first earthquake. An official representing the National Disaster Management Authority said in several villages with populations of 1,000, only 100 out of an estimated 300 houses remained intact.
Over 15 villages were destroyed, three others were severely damaged and 38 were moderately affected. The village of Nayeb Rafi was completely razed and nearly 80 percent of its population perished. In Siah Aab, Zinda Jan District, 300 inhabitants perished. In the Kushk District, more than 200 houses were damaged or destroyed to some extent. Entire families, including some with 30 members, were reportedly trapped under the rubble. In the village of Sarboland, dozens of houses were levelled and a resident said at least 30 people died. Up to 170 people were reported to have died in the village of Kashkak. Hundreds of people remained trapped beneath collapsed ruins, said a government official on 8 October.
Medieval-era minarets in Herat also sustained damage. Plaster from walls fell while parts of buildings collapsed in the city. In Iran's Razavi Khorasan province, one person in Torbat-e Jam was injured and minor damage to houses occurred in Taybad.
11, 15 and 28 October earthquakes The 11 October earthquake killed three people and injured at least 169. Of the injured, 153 were in Herat, 13 were from Badghis, and three were from Farah provinces. Many people were living outdoors because of damage to homes from the first two quakes when the third earthquake struck in the early morning. The governor's office in Herat said several neighbouring districts that were badly affected by previous earthquakes had experienced "huge losses" following the 11 October shock. This earthquake destroyed all 700 houses in Chahak, a village undamaged by the previous earthquakes. The Herat–Torghundi highway was blocked by a landslide. In Herat, damage was limited; bricks from the Akhtaruddin Castle collapsed and parts of its walls fractured. Several minarets also collapsed. Parts of rooftop of the Great Mosque of Herat fell and scattered debris into the floor; the Herat Citadel was also damaged.
The earthquake on 15 October caused four deaths, 160 injuries and additional damage in the eastern districts of Herat city. Several villages were completely destroyed and power outages occurred in most of Herat Province. Two people were also injured in Torbat-e Jam, Iran. The 28 October earthquake injured 13 people and caused additional property damage in Herat.
Search and rescue
The earthquakes occurred at a time when the region was struggling to cope with multiple crises such as displacement caused by decades of war, a years-long drought, and a huge reduction in foreign aid since the Taliban takeover in 2021.
The World Health Organization dispatched 12 ambulances to Zinda Jan District to transport casualties to hospitals. The United Nations dispatched four ambulances carrying doctors and psychosocial support counsellors to a hospital. The Associated Press reported on 9 October that three mobile health teams were expected to be in Zinda Jan District. Five medical tents designed to assist 80 patients were established by Doctors Without Borders at Herat Regional Hospital. Seven teams of the Afghan Red Crescent Society were involved in rescue efforts while more teams were expected to arrive from eight other provinces. A spokesman for the organization said people made homeless were residing at a temporary shelter. The organization also provided tarpaulins, water storage containers, kitchen appliances, blankets and many other essentials. UNICEF distributed 10,000 hygiene kits, 5,000 family kits, 1,500 sets of winter clothes and blankets, 1,000 tarpaulins, and basic household items to the area.
The national director of World Vision Afghanistan said on 9 October that "the situation is worse than we imagined", adding that people were still attempting to rescue those trapped under debris with their hands. Communication outage and blocked roads hampered rescue missions. In affected villages, residents used shovels and their bare hands to retrieve survivors beneath the rubble. An Afghan police spokesperson said on 8 October that the affected people required food and shelter. Personnel from the military and nonprofit organizations such as the Red Crescent also participated in rescue missions. The World Food Program said their workers were distributing food packages. Food packages were ready for 20,000 people; each package sufficient to sustain a family of seven for a month. The organization was also preparing to provide food support for up to 70,000 people. Athlete Rashid Khan pledged his Cricket World Cup fees to help victims of the earthquake and announced that a fundraising campaign would be set up.
A provincial health department official said over 200 bodies were transported to hospitals and many of the dead were women and children. The main hospital of Herat prepared for the large inflow of victims by lining-up beds outside. At Herat Hospital, a health worker said vans carrying bodies were arriving every minute. Many health workers at the hospital were overwhelmed at the number of injured and the morgue had been overrun. The Taliban governor's office in Kandahar said 10 teams including 37 doctors and nurses were sent to Herat Province. Kandahar's public health director said the teams were also transporting 2 tons of medicine.