Evidence for a Flood: The Black Sea and the Scientific Basis for Noah’s Tale

"...the fountains of the great deep [were] broken up, and the windows of the heavens were opened. And the rain was upon the earth forty days and forty nights." This quote from the Book of Genesis is part of a familiar tale — the story of Noah's flood. Scholars have known for a long time that the Bible isn't the only place this story is found — in fact, the biblical story is similar to a much older Mesopotamian flood story in the epic of Gilgamesh.

Scholars usually attribute things like the worldwide occurrence of flood stories to common human experiences and our love of repeating good stories. However, recently scientists have started to uncover evidence that Noah's flood may have a basis in some rather astonishing events that took place around the Black Sea some 7,500 years ago. Sediment layers suggest that 7,500 years ago Mediterranean water roared into the Black Sea, marking a catastrophic transition for the region.

The Glacial History and Sea Level Changes

The scientific version of Noah's flood actually starts long before that, back during the last great glaciation some 20,000 years ago. This was a time when the earth looked very different from what we are used to today. Thick ice sheets extended down from the North Pole as far as Chicago and New York City. All that water had to come from somewhere, so ocean levels were about 400 feet lower than they are today.

In essence, water that evaporated from the oceans fell as snow rather than rain. During this period, meltwater from the European glaciers flowed down to the Black Sea basin, then out through a river channel into the Mediterranean. Because the Mediterranean is connected to the world ocean at Gibraltar, it was also 400 feet lower than it is today, so this flow of fresh water through the Black Sea was downhill.

The Theory of the Black Sea Deluge

Two geologists at Columbia University's Lamont-Doherty Earth Observatory, William Ryan and Walter Pitman, have offered a new theory of what happened next. They postulate that as time went on, the world warmed, the glaciers retreated and meltwater from the European glaciers began to flow north, depriving the Black Sea of its main source of replenishment. The level of the Black Sea began to drop, and the area adjacent to present-day Crimea and the Sea of Azov became dry land.

At this point, the level of the Black Sea was several hundred feet below that of the Mediterranean, and the two were separated by the barrier of the Bosporus, then dry land. This situation, with the world ocean rising while the Black Sea was falling, could not last forever. Eventually, like a bathtub overflowing, the Mediterranean had to pour through into the Black Sea basin.

Geological Evidence from Sediment Cores

We know such things because sediments reveal history. Ryan and Pitman began taking cores of the present-day Black Sea which seemed to be telling a strange story indeed. At the very bottom of the cores, dozens of feet below the present seafloor, they found layered mud typical of river deltas. Carbon-dating of shells in this mud indicates that it was laid down between 18,000 and 8,600 years ago.

This data showed that an area of the Black Sea about the size of Florida might have been much like the lower Mississippi Delta today — rich farmland with an abundant supply of fresh water. Directly above the layers of mud is a layer of what Pitman calls "shell hash" — an inch-thick layer of broken shells — overlain by several feet of fine sediment of the type being brought into the Black Sea by rivers today.

Key Geological Timeline

Time Period	Geological Event
20,000 years ago	Last great glaciation; ocean levels 400 feet lower than today.
18,000 – 8,600 years ago	Layered mud laid down in river deltas (present-day Black Sea floor).
7,500 years ago	Mediterranean water roared into the Black Sea basin.

The idea that ocean basins can flood catastrophically during periods of rising sea levels is nothing new in geology. Five million years ago, a similar event occurred when the present-day Mediterranean was created as ocean water began pouring back into the former sea from the Atlantic.