On 22 May 1766, an earthquake of approximately 7.5 magnitude units and a subsequent water surge triggered a catastrophe in Istanbul, leaving behind collapsed houses, destroyed port facilities and thousands of victims. The origin of the quake was located along the North Anatolian fault in the Sea of Marmara. It was the last major earthquake to hit the metropolis on the Bosporus.
Click here for original story, Istanbul: Seafloor study proves earthquake risk for the first time
Source: Phys.org