There was a M5.6 earthquake located in the Gulf of Saros-just west of Marmara Sea, Turkey. The focal mechanism is consistent with right-lateral slip on the main strand of the North Anatolia fault (called the Ganos fault there. The onshore Ganos fault ruptured in a larger than M7 quake in 1912. I don't know if that part of the offshore fault broke then...Maybe the West to east prograssion of quakes over the last 70 years skipped right over the part nearest Istanbul, and the next large quake will be in the Aegean. On the other hand, I would guess that this quake slightly increased the shear stress and weakened the section near Istanbul-but we'll wait for those who do that work.....Chris