A strong earthquake measuring 6.1 on the Richter scale struck Turkey on Monday night, shaking Istanbul and several Aegean islands.

According to the Euro-Mediterranean Seismological Centre (EMSC), the quake occurred in Balıkesir Province and was felt in many parts of the country. The Disaster and Emergency Management Authority (AFAD) reported that the focal depth was 6 kilometers.

Balıkesir ve çevre illerden hissedilen bir deprem oldu.

AFAD Balıkesir'deki depremin büyüklüğünü 6.1 olarak açıkladıhttps://t.co/us5i9Rvz5s pic.twitter.com/pD27YaTh2O

— milliyet.com.tr (@milliyet) October 27, 2025

In addition to Balıkesir, tremors were felt in Izmir, Kütahya, Yalova, Istanbul, Manisa, Uşak, Aydın, Eskişehir, Sakarya, Yalova, and Tekirdağ.

Aftershocks have already been recorded, with the strongest so far measuring 4.2 Richter.

What Lekkas Says About the Quake

According to Efthymis Lekkas, president of Greece’s Earthquake Planning and Protection Organization (OASP) and professor of Geology, the quake had the same epicenter — southwest of Bursa — as the 6.0-magnitude earthquake on August 10. He explained that the tremor came from the same fault complex, not the North Anatolian Fault.

Lekkas added that there is no particular cause for concern for Greece, though it remains to be seen whether the shallow quake — with a focal depth of less than 10 kilometers — has caused damage.

Local reports from Lesvos (stonisi.gr) confirm that the quake was strongly felt in the city of Mytilene and surrounding villages on the island.