The quake was also widely felt in Turkeys largest city of Istanbul, located about 170 kilometers west of the epicenter.
The quake occurred on one of the most dangerous fault lines in the world, known as the North Anatolian Fault running through northern Turkey: here, the Anatolian micro-plate to the south that comprises most of Turkeys landmass, is moving westward along the boundary with the Eurasian plate to the north.
The motion amounts to 23-24 mm per year and occurs in distinct slips along... [see source for more information]