Author(s): Quirin Schiermeier [1]

[illus. 1] It sounds like a question more suited to the history of religion than science. Yet it is the driving force behind a whole field of geological research. Could a real event have inspired the Judeo-Christian story of Noah's flood -- a deluge lasting 40 days and 40 nights that drowned our sinful predecessors, save one couple and their family, who took refuge with their zoo aboard a wooden ark?

The possibility has its roots in a paper published seven years ago by marine geologists William Ryan and Walter Pitman of Lamont-Doherty Earth Observatory in Palisades, New York [1]. The event that became Noah's flood in the Bible, they hypothesized, was actually a massive flood of the Black Sea basin, which until roughly 8,000 years ago held a large freshwater lake. Then, cataclysmically, sea water burst through a natural dam blocking the narrow Bosporus Strait and raised the level of the lake some 100 metres in just a few years, inundating Neolithic settlements along its shores. Ryan and Pitman subsequently popularized the idea in a book [2].

This 'sudden infill' hypothesis has since become the subject of a prolonged argument between geologists, palaeontologists, oceanographers and archaeologists. Although most of them are not interested in the Biblical part of the question, they would very much like to know whether such a dramatic event happened. And despite an enormous amount of fieldwork, the jury is still out.

Now a group of geologists has taken a novel approach. Previous efforts searched for archaeological evidence of disrupted settlements or for geological evidence of the encroachment of the sea. The new approach, conceived by Mark Siddall, a young oceanographer until recently at Southampton Oceanography Centre, UK, and now at the University of Bern in Switzerland, begins in the lab with computer models of how a massive flood would transform the Black Sea basin. These results are then compared to existing geological features. And lo: most of the predicted effects seem to exist [3].

[illus. 2] Until now, most work on the flood has concentrated on its timing, rather than on its actual dynamics. But as Siddall is not concerned about whether the flood actually influenced writers of the Bible, he says that it doesn't really matter when it occurred. More interesting, he says, is what such an extreme event would have looked like to an observer standing on the edge of the Bosporus, and what permanent records it would have left on the sediment.

Siddall developed a fascination with the question as a PhD candidate in Southampton. Two years ago, he flew to New York to...