Engines of Our Ingenuity

No. 1192:
BLACK SEA

by John H. Lienhard

Click here for audio of Episode 1192.

Today, let's ride the wake of an old old flood. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Gilgamesh, hero of Babylonian mythology, went on a journey to find Utnapishtin, who had survived the flood. Gilgamesh meant to make Utnapishtin tell him how to escape death. So the great flood of antiquity tiptoes into yet another old myth. Maybe there were several floods. This Babylonian story can be traced back further than Genesis in its written form. But it's hard to know how much further the stories go in oral form. One common thread catches our ear, however: Noah lived 950 years, while Utnapishtin learned to escape death entirely.

In any case, scientists now offer, as a candidate, the flooding of the Black Sea in 5500 BC. If, as some think, the Gilgamesh story refers to a Sumerian ruler who lived around 2600 BC, the Black Sea flood would be much too early and somewhat far to the North. Still, Gilgamesh had to travel to find Utnapishtin, and myths do leapfrog from one real event to another.

The Black Sea flood was a truly major upheaval. Here's what happened: The last ice age retreated 12,000 years ago and the world began warming. As it did, ice melted and oceans rose, while lakes began to evaporate and shrink.

The Black Sea was a great freshwater lake in those days and, as the new technology of farming matured eight thousand years ago, farmers moved into the lands around it.

By 5500 BC, the lake lay 500 feet below sea level. Then the thin strip of land between the salt Sea of Marmara and the freshwater Black Sea gave way. A terrible gush of water cut through, creating the Bosporus channel. The flow was 400 times greater than Niagara Falls — making a sound heard over sixty miles away.

The water advanced a half-mile a day. Within three months it'd flooded 60,000 square miles of farmland. The Black Sea had turned from fresh water to salt, and its size increased by a third. The farmers fled, carrying their art to places that'd never known farming. Stone-age farms first appeared in the valleys and plains of central Europe about 200 years later.

The flood turned the high ground of the Crimean Peninsula into a near island. It created the Sea of Azov, nested above the Crimea and connected to the Black Sea by a small channel. The Sea of Azov remains a nearly freshwater body, fed by the Don River.

The rest of the Black sea is fed by the fresh Danube and Dnieper river water, but it's also fed by the salty Mediterranean. The fresh river water flows out through the Bosporus at surface level, while the heavier salt water flows in underneath it — in a fittingly Byzantine arrangement of flows.

And what about Noah's and Utnapishtin's floods? We cannot know, of course. But the Black Sea certainly provides a dramatic enough basis for the grand myths — that we still remember today.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


Wilford, J. N., Geologists Link Black Sea Deluge to Farming's Rise. The New York Times, SCIENCE TIMES, Tuesday, December 17, 1996, pp. B5 and B13.



Image courtesy of the Documents Department, UH Library


The Engines of Our Ingenuity is Copyright © 1988-1997 by John H. Lienhard.

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