The institute said the quake struck off the North Aegean island of Bozcaada at 4:16 p.m. at a depth of 8.4 kilometers below the surface of the Earth. The quake was strongly felt in Ä°stanbul as well as in a number of Thracian and Aegean provinces. There were no immediate reports of injuries or damage.
Earthquakes frequently rattle Ä°stanbul, but most are minor and cause little or no damage. The most recent devastating earthquake to strike Ä°stanbul occurred in Aug. 17, 1999. A 7.6-magnitude tremor struck at 3:02 a.m. local time, killing tens of thousands of people. Scientists believe a powerful earthquake is likely to strike Ä°stanbul or its environs in the next 30 years. Earthquakes are frequent in Turkey, much of which lies atop the active North Anatolian fault.
"It was one of the strongest earthquakes we have experienced," Mustafa Mutay, the mayor of the Turkish island of Bozcaada off Çanakkale, told the state-run Anatolia news agency. "There was some panic during the quake, but things have returned to normal and there is no damage."
The Athens Geodynamic Institute in Greece put the magnitude at 5.8 and said the temblor occurred between the Greek islands of Lemnos and Lesvos, near the Turkish coast. The quake was mildly felt in Athens.
The US Geological Survey gave a preliminary magnitude of 5.7.