The Black Sea flood is dated to 7,600 years ago. Maybe?
This could have triggered the breach of the Bosphorus dam if the Mediterranean was wet at the time. BTW, there are apparently stories of a time the Bosphorus was dry and will be dry again.
Simple ~ earlier tsunami damages Eastern Mediterranen natural dam between it and Black Lake, and this, in turn, leads over several centuries of quite normal rainfall, etc. to a final breakdown which then floods the Lake.
7,600 BP, could that have been major flooding caused by the eruption of Mt. Mazama, leaving the 6 mile diameter Crater Lake? This was more than 4 times the volume of Mt. Pinitubo, and look at the 500 year flood we had in the Mississippi basin. Perhaps the tsunami 8,000 years ago washed away part of the barrier to the Black Sea, and major rains from Mt. Mazama finished the job?
Incidentally, does anyone have information on the impact of the major pyroclastic flow at Etna around 1500 BC, plus or minus 50 years. I have done some googling, but not come up with anything much except for the name of the depression in the mountainside that was left behind.