 A damagedbar in Kos | |
   | |
| UTC time | 2017-07-20 22:31:11 |
|---|---|
| ISC event | 610790782 |
| USGS-ANSS | ComCat |
| Local date | 21 July 2017 (2017-07-21) |
| Local time | 01:31 (EEST) (UTC+03.00) |
| Magnitude | 6.6Mw |
| Depth | 7.0 km (4.3 mi) |
| Epicenter | 36°55′23″N27°24′54″E / 36.923°N 27.415°E /36.923; 27.415 |
| Type | Normal faulting |
| Areas affected | Greece Turkey |
| Max. intensity | MMI VII (Very strong) |
| Tsunami | Up to 1.9 m (6.2 ft) along the Greek and Turkish coasts |
| Aftershocks | 390 aftershocks (M > 3.0) in 1 year, the highest being aMw(KOERI) 5.3 |
| Casualties | 2 killed, 480 injured |
On 21 July 2017, a large earthquake measuring 6.6 on themoment magnitude scale struck close to the tourist locations ofKos inGreece andBodrum inTurkey, killing 2 people and injuring hundreds. Mostly referenced as the2017 Bodrum–Kos earthquake, this earthquake generated a tsunami which was one of the largest tsunamis in theMediterranean Sea region.
The EasternMediterranean where the earthquake occurred is an area of complextectonics related to the collision of theEurasian plate,African plate andArabian plate.Continental collision occur here, includingsubduction of the African platelithosphere under the Eurasian plate (specifically, theAegean Plate and theAnatolian Plate); thetransform boundary between the African plate and Arabian plate which forms theDead Sea Transform; and theconvergent boundary separating the Aegean and Anatolian Plate.[1]
TheAegean region, is a seismically and volcanically active area that has been deformed under a north-to-south extensionaltectonic regime at up to 30-40mm/yr since thePliocene. Where the epicenter of the earthquake is located, theGulf of Gökova is an east–west trending asymmetricgraben measuring 120 km (75 mi) long and 5–30 km (3–19 mi) wide. It developed onnappes which are filled withPliocene toQuaternary marinesediments. Thedepression is bordered by theDatça Peninsula to the south,Kos to the west, and theBodrum Peninsula to the north. The northern part of the graben is dominated by the Gökova Fault Zone which is one of the most seismically active fault structures in southwesternAnatolia. It is an east–west and northeast–southwest trending arc-shaped fault zone.[2] The Gökova Fault Zone contains a complex fault pattern which could be related to the interaction between deepstrike-slip faults and shallower normal faults. According to observed geological markers, the combined offset of the fault zone is about 1,000 m (3,281 ft) since the Pliocene period. This suggests a slip rate of around 0.2 mm/yr.[3] Most faults in the fault zone are underwater while some are visible on land.[4]
In historical times, many large earthquakes have struck the Gökova associated with the fault zone. Historical earthquakes with a record of damage include 412 BC, 227 BC, 199–198 BC, 24 BC,141 AD, 174 AD, 344 AD, 474 AD,554 AD, 1493 AD, 1851 AD, 1863 AD and 1869 AD events. In the 1493 event, the city of Bodrum was totally destroyed.[5] In the 20th century, large instrumentally recorded events (events recorded byseismometers or other instruments) include those of1933 and 1941 with magnitudes of 6.4 and 6.0 respectively.[6]
TheMw 6.6 earthquake struck at 01:31 on 21 July 2017 at a depth of 7 km. It caused shaking assignedMMI VII (Very strong).Focal mechanism solutions of the earthquake indicate this event was generated by an east–west trending normal fault within the lithosphere within the Aegean Plate.[7]Coulomb stress modeling showed the earthquake ruptured an area with around 16 km (10 mi) length and 11 km (7 mi) width on a west-southwest to east-northeast direction.[8]
Ground deformation and displacement of the mainshock faulting were observed viaGPS andinterferograms. Most of the deformation was observed inKaraada, near the epicenter.[9]
Relative to the large magnitude and large depth, the earthquake generated a tsunami which was one of the largest ever recorded in the Mediterranean since records began in426 BC.[10] The tsunami was first picked up by atide gauge in Bodrum, which measured 0.11 m (4 in). In the next few weeks after the main earthquake, field surveys were performed. As a result of the surveys, tsunami inundations as much as 100 m (328 ft) were observed with a run-up height of 1.9 m (6 ft). Many dead fish were found, cars were dragged and boats were damaged.[11]
Extensive damage took place on the island of Kos, and to a lesser degree in the area around Bodrum. On Kos, the old town was worst affected, with the cathedral, the 18th century Defterdar mosque, and a 14th-century castle being badly damaged. The main harbour had its floor crack as a result of the tremor, and was subsequently declared unsafe for use by government officials, who rerouted all ferries to the smaller port town ofKefalos in west Kos.[12]
Two fatalities were reported on the island, in addition to more than 120 injuries.[12] The two dead were identified asTurkish andSwedish nationals, and were killed when the upper facade of a bar collapsed on top of them.[13] Seven seriously injured people on Kos were flown to hospitals inAthens andHeraklion, including two men from Sweden andNorway in critical condition. Around 360 people were injured in Bodrum, many after jumping out of windows in panic, but none of the injuries were regarded as serious.[12][14][15]
