Black Sea deluge hypothesis

[1][2] In 1997, William Ryan, Walter Pitman, Petko Dimitrov, and their colleagues first published the Black Sea deluge hypothesis.

They proposed that a catastrophic inflow of Mediterranean seawater into the Black Sea freshwater lake occurred around 7,600 years ago, c. 5600 BCE.

The event flooded 100,000 km2 (39,000 sq mi) of land and significantly expanded the Black Sea shoreline to the north and west.

They argued that the catastrophic inflow of seawater resulted from an abrupt sea-level jump that accompanied the Laurentide Ice Sheet collapse and the ensuing breach of a bedrock barrier in the Bosporus strait.

[8][9] Popular discussion of this early Holocene Black Sea flood scenario was headlined in The New York Times in December 1996[10] and later published as a book.

[9] In a series of expeditions widely covered by mainstream media, a team of marine archaeologists led by Robert Ballard identified what appeared to be ancient shorelines, freshwater snail shells, drowned river valleys, tool-worked timbers, and man-made structures in roughly 100 metres (330 ft) of water off the Black Sea coast of modern Turkey.

These extensive meltwater flooding events linked several lacustrine and marine water bodies, starting with the southern edge of the Scandinavian and southward, through spillways to the Manych-Kerch and Bosphorus, ultimately forming what has been referred to as the Cascade of Eurasian Basins.

[27] In 2011, several authors concluded that "there is no underwater archaeological evidence to support any catastrophic submergence of prehistoric Black Sea settlements during the late Pleistocene or early Holocene intervals".

[28] A 2012 study based on process length variation of the dinoflagellate cyst Lingulodinium machaerophorum shows no evidence for catastrophic flooding.