2002 Afyon earthquake
The Afyonkarahisar Province of western Turkey was struck by a 6.2–6.7 earthquake on 3 February 2002 at 10:11:28 local time. It had a maximum felt intensity of IX on the Modified Mercalli intensity scale. It caused the deaths of 46 people and a further 332 injuries, with 15,700 buildings affected, the vast majority of them in the communities of Eber, Çay, Afyonkarahisar and Sultandağı.
Tectonic setting
Most of western Turkey lies in an area of extensional tectonics that extends into the Aegean Sea. The cause of the extension is thought to be the rollback of the subducting slab of the African plate that dips northwards beneath the Aegean. The overall N–S extension has resulted in a series of NW–SE to W–E trending seismically active normal faults with associated rift basins. The Afyon–Akşehir Graben lies in the hanging-wall of the low-angle Sultandağı Fault and contains nearly 1 km of late Miocene to Quaternary sedimentary fill. Part of this fault ruptured during a magnitude 6.0 earthquake in December 2000.Earthquake
The earthquake had a magnitude in the range of 6.2–6.7, with the United States Geological Survey reporting a magnitude of 6.5. The observed focal mechanism is consistent with normal faulting along a fault trending WSW–ENE, although the local trend of the basin-bounding fault is closer to WNW–ESE. The distribution of the aftershocks, however, is consistent with a rupture along part of the Sultandağı Fault of about 40 km in length. It also suggests that the rupture propagation was almost unidirectional towards the northwest, with the mainshock close to the southeastern end of the rupture. According to the USGS, of surface faulting with vertical offset in the Çay–Sultandağı area, while two new hot springs formed in the area and others changed their flow rates.The earthquake had a maximum Modified Mercalli intensity of IX. A USGS seismic installation at Afyonkarahisar city recorded 0.1157 g in peak ground acceleration and 40.41 cm/s in ground velocity; the station data corresponded to MMI VIII shaking. A Mercalli intensity of VII and a pga of 0.25 g was estimated in Çay and other areas up to southeast of the town, based on damage to reinforced concrete buildings in the town. MMI VI was estimated within an radius of the epicenter.
In total, there were more than 600 aftershocks, including 17 with a magnitude of 4.0 or higher by the end of 2002. The largest aftershock, measuring 5.8–6.0, occurred at 09:26:43 UTC near the western end of the Sultandağı Fault. Analysis of the coulomb stress transfer associated with the nearby M6.0 earthquake on 15 December 2000 suggests that these stress changes triggered the 2002 mainshock. The epicentre of the mainshock lies near the termination of the rupture associated with the earlier earthquake, consistent with this interpretation.
Damage and casualties
In Afyonkarahisar Province, 44 deaths and 318 injuries were recorded. In Konya Province, one person suffered a fatal heart attack and seven others were injured from jumping from windows and balconies in the city of Konya, with another death and seven injuries recorded in Akşehir. There was significant damage in eight of the 18 districts in Afyonkarahisar Province and some damage in Akşehir in Konya Province. A total of 4,051 residential and 339 commercial buildings either collapsed or were badly damaged. A further 10,402 residential and 884 commercial buildings suffered either low or medium levels of damage. The most damaged building type was the traditional Himis style, which consists of timber frames with adobe and rubble infill and heavy roofs. Collapses of this building type were responsible for causing most of the deaths and injuries in the earthquake. The district of Çay suffered the most damage and had the greatest number of fatalities, with 1,226 residential buildings and 245 commercial buildings heavily affected.Çay District reported 23 fatalities and 76 wounded; the village of Eber alone reported 15 fatalities and 30 injuries, with 300 of the 450 households severely damaged or destroyed by the earthquake. There were also 15 deaths in Sultandağı. In Bolvadin, two people were killed, 200 more were injured, 4,041 residential buildings and 697 commercial buildings were affected. Afyonkarahisar city also reported two fatalities and 1,153 severely affected residential and commercial buildings, with 1,773 other structures receiving varying degrees of damage in the city. Five additional villages in Afyon Province reported destroyed homes, with collapsing barns killing numerous livestock and multiple building fires reported.