A Flood’s Hold on Human Memory

Cultures across the globe have an ancient flood story.

Genesis tells of Noah, who built an ark to rescue his family and each species of animal, two by two.

The older Babylonian epic of Gilgamesh tells of Utnapishtim who, warned by the water god Enki, built a boat to save his family, animals and artisans from a world-devouring flood.

Greeks and Romans grew up with the story of Deucalion and Pyhrra, who saved their children and a collection of animals by boarding a vessel shaped like a giant box. Even American Indians have stories of world-devastating floods.

Geologists have never been able to find any evidence that the whole Earth was inundated in a massive flood. But recent evidence suggests that there may, in fact, have been a flood in the Black Sea so cataclysmic in scope that it could have remained burned in human memory for thousands of years, passed down first in oral histories and ultimately in written form.

About 7,000 years ago, a group of researchers now believe, the Mediterranean Sea crashed through a natural earth dam that blocked what is now the Bosporus strait, flooding what at the time was a relatively small freshwater lake. For as long as two years, water rushed through the narrow Bosporus with the flow of 200 Niagara Falls, eventually inundating an area the size of Florida.

Water levels in the Black Sea rose 6 inches per day. On the relatively shallow north side of the lake that would have been enough for the rising waters to consume up to a mile of shore per day, forcing not only residents but also farm animals and wild creatures to flee in panic.

The erstwhile residents fled to areas as diverse as Egypt, western Europe and central Asia, taking with them their languages, cultures and searing memories of the flood that forced their flight. The Book of Genesis was not composed until several thousand years later, but the Noah story may well incorporate memories of that great flood.

A variety of geological evidence had previously suggested such a scenario. Last month, famed deep sea explorer Robert Ballard of the Woods Hole Oceanographic Institution provided strong new evidence supporting the theory, announcing the discovery of the original lake’s southern beach under 550 feet of water.

“I’m not sure whether it was Noah’s flood or not Noah’s flood but . . . there was a flood,” said marine geologist David Mindell of the Massachusetts Institute of Technology, who participated in the expedition.

“If you want to say the Black Sea flood is Noah’s flood, who’s to say no?” added Hershel Shanks, editor of the Biblical Archeology Review.

Effects of Ice Age

The link between the Black Sea and flood stories was originally suggested by marine geologists William Ryan and Walter Pitman of Columbia University, first in a series of research articles, and ultimately in a book published earlier this year called “Noah’s Flood.”

The stage was set for the flood by the world’s most recent ice age, which peaked about 12,000 years ago, Ryan and Pitman maintain. The frigid weather tied up a large portion of the Earth’s water at the poles, lowering ocean levels sharply and cutting the Black Sea off from the Mediterranean.

With the influx of water halted, the level of this isolated lake--which geologists call New Euxine Lake--fell as much as 450 feet below the Mediterranean, exposing a fertile shoreline that became the home of tens or even hundreds of thousands of settlers.

But as the ice age ended and the glaciers receded, the world’s oceans started rising again. The Mediterranean slowly rose to the sill of the Bosporus land bridge. Ultimately--perhaps triggered by a major rainstorm or a minor earthquake--the land bridge began to give way. As erosion ate away at the dam, a trickle of water became a river, then a flood. The rush of the water would have been audible as much as 300 miles away, researchers believe.

What tantalizes archeologists is that the heavy saltwater from the Mediterranean plunged to the bottom of the basin, with the leftover freshwater from New Euxine Lake floating on top. Because there has been little mixing of the two layers since, that is how the situation remains today, with 500 feet of freshwater covering as much as 7,000 feet of saltwater.

And because there is no mixing between the layers, no oxygen enters the lower layer and nothing lives there. There are no marine worms and bacteria to bore into ships and destroy the wood. There is nothing even to consume the fabric sails. Ballard believes there could be 7,500 years worth of pristine shipwrecks preserved on the lifeless bottom and he hopes to find many of them.

This summer, Ballard and his team sailed from the Black Sea port of Sinop, Turkey, on the southern shore. They dropped a side-scan sonar instrument over the side of their boat and found exactly what they were looking for--and what had been predicted by Ryan and Pitman.

“There was the classic beach profile: The flat shore area, the beach berm leading down to the old water level, and a sandbar just offshore,” Ballard said. “It looked like any beach on Earth, except it was 550 feet under water.”

Ballard scooped up a bucket of shells from the ancient shoreline and sent them to marine chemist Gary Rosenberg of the Academy of Natural Sciences in Philadelphia. Two shells were extinct freshwater mollusks, presumably dating from before the flood, and seven were saltwater mollusks from the post-flood era.

Radiocarbon dating showed that the youngest of the freshwater shells was about 7,500 years old, while the saltwater shells dated from a maximum of 6,900 years ago, neatly bracketing the date when Ryan and Pitman believe the flooding occurred.

“It feels good,” Pitman said of Ballard’s confirmation of the theory.