Osman Bektaş warns against single‑scenario model for Istanbul earthquake

Prof. Dr. Osman Bektaş, a geotechnical expert at Karadeniz Technical University, has repeatedly cautioned that the seismic risk in the Marmara region and the potential Istanbul earthquake cannot be reduced to a single “7‑plus magnitude locked‑fault” scenario. He argues that the notion of a fully “locked” East Marmara and Islands Fault is not fully supported by current data, noting that thick, water‑saturated sediment layers can mask GPS, InSAR and acoustic‑seafloor measurements, and that a lack of repeating micro‑earthquakes does not prove a fault is locked.

Bektaş emphasizes the importance of the next 3‑7 days of seismic activity. While micro‑earthquake clusters (magnitudes below 3.5 at depths of 6‑9 km) are being recorded by AFAD, he says they alone do not guarantee a larger event, but a rise to magnitude 4 or higher within this period would be a critical indicator. He calls for the scientific community and authorities to discuss multiple fault‑behavior models—including the possibility of slow slip (creep)—rather than focusing on a single prediction.

His social‑media statements repeat that “İstanbul depreminde tek bir senaryoya mahkum değiliz” (we are not condemned to a single scenario) and that preparation should consider a range of possible outcomes, urging continued monitoring and preparedness regardless of the exact model.