Marmara Sea region in northwestern Turkey with the North Anatolian Fault Zone (NAFZ) separating Eurasia from Anatolian. The offshore Marmara fault where a major earthquake is overdue is indicated by the red line. The black lines to either side are the two last major ruptures of the region, the 1912 Ganos and the 1999 Izmit earthquakes. The Marmara section has not produced a large earthquake since 1766 but is know to rupture every ~250 years based on historical records. The yellow stars mark the repeating earthquakes found in the now published study indicating fault creep (green rectangle) while the fault portion offshore of Istanbul (blue rectangle) is locked.