Turkey’s emergency management agency says an earthquake with a preliminary magnitude of 6.2 has shaken Istanbul. Wednesday’s earthquake was centered in the Sea of Marmara off Istanbul. There were no immediate reports of damage or injuries. It was followed by several aftershocks, including one measuring 5.3. Turkey is crossed by two major fault lines and earthquakes are frequent. A magnitude 7.8 earthquake on Feb. 6, 2023, and a second powerful tremor that came hours later, destroyed or damaged hundreds of thousands of buildings in 11 southern and southeastern Turkish provinces, leaving more than 53,000 people dead.