Thanks.
Around 5600BC, or 7600 years ago. What happened was that as the Ice Age waned, a land barrier between the Mediterranean and the Black Sea was finally breached. At that time the Black Sea was a freshwater lake. According the calculations of Pitman and Ryan, "10 cubic miles of water poured through [the Bosporus] each day, two hundred times what flows over the Niagra falls, enough to cover Manhattan Island each day to a depth of over half a mile." They estimated that the roar of the rushing water would have been audible at 300 miles distance, the speed of the inflow would have been some 50 miles per hour, the rise of the Black Sea would have been 6 inches per day, and all around the world the oceans would have been lowered by
a foot in order to supply this huge new addition to their capacity.
And no surprise -- the mountains of Ararat are way up there not that far from the Southeastern shores of the Black Sea -- and quite a trek from the rest of the action that happened in the Bible. Almost all the action in the Old Testament happens in what is today Egypt, Israel, Jordan, Syria, or Iraq. Except for -- TA DA -- Noah's Ark and the flood which is way up north of the rest of the action. Interesting, yes?