Archaeologists probe Black Sea abyss
According to the Old Testament, the great flood lasted for 40 days and 40 nights, and submerged the whole Earth.
Scientists have never found Noah or his ark, but they know about the flood. It happened about 7,600 years ago when the Mediterranean Sea, swollen by melted glaciers, breached a natural dam separating it from a freshwater lake today's Black Sea.
It was a catastrophic event. Every day for two years, 42 cubic km of sea water cut through the narrow channel now known as the Bosporus, and plunged into the lake more than 200 times the flow over Niagara Falls. Every day the lake level rose 15 cm. Every day the water spread another kilometer, forcing people and animals to flee or drown, killing freshwater fish and plants by the ton and inundating forests and villages.
As the deluge filled the lake and transformed it into a sea it also created an ecosystem unique in the world: an oxygenless abyss where shipwrecks might rest for thousands of years in darkness uncorrupted by life.
The possible presence of old ships in near-mint condition on the Black Sea floor has sparked perhaps the most ambitious project ever undertaken in the emerging field of deep-water archaeology.
Since explorer Robert D. Ballard discovered the Titanic 3,800 meters beneath the North Atlantic in 1985, deep-sea experts have used ever more sophisticated robots and submersibles to plumb the world's seas, but Ballard's Black Sea Project has far more audacious goals than the discovery of a single ship. They hope to prove that literally thousands of years of history may lie intact in shipwrecks blanketed by the sterile waters of the flood.
"It's like a bathtub, but without a drain," Ballard says. "The Bosporus acts like an overflow valve, but the water can't circulate, so it lost its oxygen long ago. Such conditions exist nowhere else in the world."
In the past five years, project researchers trying to find the ancient Black Sea trade routes have studied scientific literature, history and classical texts such as the legend of Jason, whose quest for the Golden Fleece reflects the early adventures of the ancient Greeks in the Black Sea.
At project headquarters in the Turkish city of Synope, archaeologists mapped a seaport that acted as a major trading center during the Bronze Age, 5,000 years ago, and maybe even earlier. Artifacts have linked Synope to Black Sea sites north in the Crimea and west in Bulgaria, as well as to Troy, the fabled Aegean city that guarded the entrance to the Black Sea. Rather than hugging the coast, the research suggests, sailors were willing to save time and money by traveling point-to-point over waters as deep as 2,100 meters.
This summer, the project's underwater surveyors found an ancient coastline at a depth of 140 meters, just above the anoxic dead zone.
"I'm not sure whether it's Noah's flood or not," says David Mindell of the Massachusetts Institute of Technology. "But there was a flood."
The theory of the Black Sea's Neolithic catastrophe was developed by Columbia University marine geologists William Ryan and Walter Pitman over three decades of research and published this year in their book "Noah's Flood." The authors describe how the sea level worldwide began to rise as glaciers melted at the end of the last ice age 15,000 years ago. Back then, the Black Sea was a freshwater lake fed by rivers, among them those known today as the Danube, the Dnieper and the Don.
To the south, a 110-meter natural dam held back the waters of what is now the Mediterranean Sea. By 7,600 years ago, sea level probably had risen to within 5 meters of the lip of the Bosporus.
Then it flooded.
It was a one-of-a-kind event, and it had a unique result. The incoming salt water, denser than the fresh water it displaced, plunged straight to the bottom of the lake bed. As the seawater rose, the fresh water floated on top, flowing in from the northern rivers and out via the Bosporus.
This phenomenon repressed the natural heat exchange that causes water to circulate and reoxygenate in seas and lakes throughout the world. Today, the top 140 meters of the Black Sea are constantly renewed and support a vigorous marine life. The abyss leached of oxygen, lies like à cold blanket 2,000 meters deep, covering the sea floor and its secrets.
If there is no oxygen, then there should be none of the wood-boring mollusks that consume wooden ships. Normally, an old wooden wreck will appear as nothing more than a jumble of amphorae or other cargo on the sea bottom. The hull may be intact if it has sunk into the mud, but exposed wood will be eaten.
In the Black Sea, however anything on the bottom should be intact including ancient wooden ships. The Black Sea lies near the Fertile Crescent and served as a commercial waterway for civilizations from ancient Greece to Byzantium and the Ottoman Empire, so "one should have a complete chronicle of human history," Ballard says.
In 1994 he recruited University of Pennsylvania archaeologist Fredrik T. Hiebert, a specialist in ancient trade along the Silk Roads. If Hiebert could find a trade route across the Black Sea, then deep-water archaeology could find the wrecks.
Hiebert agreed to oversee a series of library studies, and found solid evidence that the ancient peoples on all sides of the waterway had a brisk interchange of goods. Roof tiles in the Crimea were stamped with the Greek word "Synope." Studies of currents and winds showed that sailors could travel the 290-km south-north route across the sea from Synope to the Crimea, though it was dangerous.
Funded by the University of Pennsylvania and the National Geographic Society, Hiebert and Ballard began work. Hiebert took charge of dry-land archaeology, while Mindell did the marine survey.
Then "Noah's Flood" was published, with its suggestion that entire cultures may lie submerged below the ancient floodwaters. The group expanded its mandate to include a search along the old coastline. Next year, Hiebert will spot likely locations for ancient settlements, and Mindell will look for them. Ballard will use a remotely operated vehicle named Jason to scout the old trade route, aided by a narrow-beam sonar that can spot a wreck through 4 meters of sediment.
The team wonders: Have the worms figured out a way to work in the Black Sea abyss, "or do the wrecks have sails?"