On 2026-10-11, the Marmara Sea experienced a 3.5-magnitude earthquake.
At 22:08 on 2026-10-11, the Disaster and Emergency Management Authority (AFAD) recorded a new tremor. According to AFAD, the quake had a magnitude of 2.9, its epicentre lay off the coast of Yalova, it struck at 22:08 local time and originated at a depth of 7.96 kilometres.
The Kandilli Observatory measured the same event and reported a magnitude of 3.0.
9, its epicentre lay off the coast of Yalova, it struck at 22:08 local time and originated at a depth of 7.
The tremor was felt in Istanbul and surrounding provinces.
The chronology of the two shocks is clear: the first, larger quake occurred on 2026-10-11 in the Marmara Sea, and the second event took place on 2026-10-11 off Yalova at 22:08.
The previous day's earthquake measured 3.5 magnitude. AFAD reported the new tremor at 2.9 magnitude, occurring at 22:08 with a depth of 7.96 km. Kandilli Observatory measured the magnitude at 3.0.