Geology professor Osman Bektaş says Istanbul quake likely under magnitude 7

Geology professor Osman Bektaş, a retired faculty member of Karadeniz Technical University, evaluated the possible Istanbul earthquake. Referring to international studies by German and Japanese scientists (2019‑2023) on fault‑creep in the Marmara Sea, he argued that the Kumburgaz segment is not fully locked and therefore cannot generate a mega‑rupture. Bektaş highlighted that the depth of fault creep increases toward Kumburgaz, causing the seismogenic zone to become very shallow, which limits the potential for a single M 7+ rupture. Consequently, he concluded that the expected Istanbul earthquake should be below magnitude 7, contrary to the often‑cited 7.4 scenario.

Bektaş also noted that past M 5‑6+ events along the main Marmara fault (2011, 2012, 2019, 2025) did not trigger a continuous large‑scale break, and the Avcılar‑Kumburgaz segment shows low tension accumulation. He emphasized that future seismic activity in the region will likely involve smaller, independent segments rather than a single large shock.