The Main Marmara Fault (MMF) in northwestern Turkey represents the highest seismic risk in wider Europe.[1][2] The study identifies a series of eastward-propagating magnitude-above-5 events and a gradual eastward partial rupture of the IMF over the past 15 years or so.[1][2][3] They include creeping segments and transitional segments, with the most recent seismicity located near the locked segment of the Princes Islands south of Istanbul with the potential to trigger a magnitude 7 earthquake.[1][2] The 2025 magnitude 6.2 earthquake was the largest on the IMF in over 60 years and partially overlapped with the 2019 magnitude 5.8 rupture at Silivri.[1][3] These ruptures were oriented to the east with higher seismic activity in that direction and transmitted stress to the eastern parts.[1][6] An approximately 15–20 km long region of low seismic activity remains in the Avcılar segment between Kumburgaz and Princes Islands.[3] The analysis emphasizes the need for real-time monitoring of this part of the IMF.[1][2]