William Ryan & Walter Pitman published evidence, in 1997, that extensive flooding of the Black Sea occurred through the Bosphorus around 5600 BC. Controversy still surrounds various aspects of their
theory, some even claiming that the Black Sea broke into the Aegean, an idea that may be partially true(d)(e).
Nevertheless, their conclusions were challenged in a paper(c) by Yanko, Gilbert and Dolukhanov, who offered evidence that the flooding of the Black Sea was not the rapid event claimed, but was spread over millennia, initially in the form of freshwater from the Caspian Sea via the Manych Spillway(d) as the glaciers retreated and later with seawater from the Mediterranean. The same paper concludes with the following; “The public perception that ‘Noah’s Flood’ happened there is not supported by any scientific evidence.”
Ryan & Pitman later published their theories in book form as Noah’s Flood and was understandably seized upon by many as proof of the veracity of the Bible. In fact a year before Ryan & Pitman launched their book, René & Denise Capart published l homme et les déluges, in which they linked the Black Sea with the the Deluge of Noah. A Bulgarian father and son team, Petko & Dimitar Dimitrov, refer to the pre-flood Varna civilisation existing on the Black Sea plain, but not calling it Atlantis by name. Their book is available online(a).
Inevitably, I suppose, Atlantis has been more firmly linked with this event by a number of commentators, particularly, Christian & Siegfried Schoppe(b). However, Hristo Smolenov also claimed that swathes of the Varna civilisation were inundated by the rising waters of the Black Sea but had no hesitation identifying it with Atlantis.