Ancient "Lost" City's Remains Found Under Alexandria's Waters

Alexander the Great was not the first to conquer the land where present-day Alexandria (above) now stands. Soil samples taken from beneath Alexandria's bay provide the first hard evidence of Rhakotis, a town mentioned in several histories of the region but whose existence until now had never been proven. Photograph by Ben Curtis/AP


Ancient "Lost" City's Remains Found Under Alexandria's Waters
Dan Morrison in Alexandria, Egypt
for National Geographic News
July 31, 2007

The first physical clues to a long-rumored town that existed on the site of present-day Alexandria have been uncovered—by accident.
While searching under the waves of Alexandria's East Bay for Greek and Roman ruins, archaeologists discovered signs of building construction 700 years older than Alexander the Great's invasion of Egypt.
The conquerer founded Alexandria in 332 B.C. (Related: "Alexander the Great Conquered City via Sunken Sandbar" [May 15, 2007].BELOW)
The new find is "the first hard evidence" of Rhakotis, a town mentioned in several histories of the region but whose existence had never been substantiated, said geoarchaeologist Jean-Daniel Stanley of the Smithsonian Institution's National Museum of Natural History.
And the results, which are published in the August issue of the journal GSA Today, were "a bit of serendipity," Stanley said.
Sunken Surprise
Stanley has helped the Franck Goddio Society and Egypt's Supreme Council of Antiquities search for clues to what might have caused the structural failure of Greek- and Roman-era buildings, roads, and piers now sitting at the bottom of the bay.
The team sunk a half-dozen vibracores—vibrating three-inch (eight-centimeter) hollow tubes—into the muck and silt of the bay's floor.
The tubes contained layered soil samples, or cores—some as long as 20 feet (7 meters).
Stanley took his samples back to Washington, D.C., and dated them using a radiocarbon technique.
Though he was searching for cracked or damaged rocks that might suggest how Greek-era structures had failed, he was surprised to find older signs of human endeavor.
The cores turned up lead and human waste that were more than 3,000 years old—evidence of a significant settlement centuries before Alexander stormed Egypt.
Stanley assembled a team of specialists in terrestrial magnetism, anthropology, paleobiology, and geology to examine the core samples.
After a few years of study, the team confirmed the findings did indeed point to Rhakotis.
In addition to the 3,000-year-old lead, which was used for construction, the cores contained stone building materials from central and southern Egypt.
"There are signs of a flourishing settlement going back to Pharaonic times, but it's too early to say anything about it," Mohamed Abdel-Maqsud, an Alexandria expert from the Supreme Council of Antiquities, told the Associated Press.
Jean-Yves Empereur, director of the Center for Alexandrian Studies, said he had not yet read the findings and could not comment.
Sailor Haven
The city's bay, anchored by the island—now a peninsula—of Pharos, has long been known as a haven for sailors. The bay is even mentioned in Book Four of Homer's Odyssey: "Therein is a harbor with good anchorage, whence men launch the shapely ships into the sea. ..."
When Alexander arrived in 332 B.C., he apparently agreed with Odysseus's reasoning. His new Egyptian capital would be close enough to the Nile for southern travel, but far enough away that seasonal flooding wouldn't be a problem.
Ptolemy I, Alexander's political heir, built the nearly 500-foot (152-meter) Lighthouse of Alexandria on Pharos, one of the Seven Wonders of the Ancient World.
The lighthouse served as both a beacon and a symbol of Alexandria's greatness until a pair of earthquakes sent it tumbling into the bay 1,600 years later. Alexandria today is a breezy Mediterranean city of five million people.
The next step for researchers will be unmasking the culture and people of Rhakotis, now the bay's earliest known inhabitants.
"Were they seamen, agriculturalists, traders?" Stanley said. "We don't yet know."




Alexander the Great Conquered City via Sunken Sandbar
Kate Ravilious
for National Geographic News
May 15, 2007
Changing sea levels and shifting sands helped Alexander the Great conquer the ancient island city of Tyre in one of his most famous military victories, new research shows.
In 332 B.C. the Greek military commander invaded the island just off the coast of modern-day Lebanon, then part of ancient Phoenicia.
New geological findings and computer models show that the growth of agriculture on the island caused sediment runoff, which spurred the formation of a long, thin submerged sandbar between Tyre and the mainland.
Alexander and his men cunningly exploited this sandbar, the findings suggest, to build a 0.6-mile (1-kilometer) raised path, or causeway, out of wood and stone.
Alexander's army marched from Macedonia to Egypt around 2,350 years ago, conquering every major city in turn.
But capturing the naturally protected Tyre posed a huge military problem.
"Building a bridge out to sea was a real challenge at this time," said Nick Marriner of the University of Aix-Marseille in France, lead author of the study.
Marriner's team reports its findings in the current online issue of the Proceedings of the Academy of Sciences.
No Cranes or Concrete
To understand how Alexander constructed his causeway, Marriner and his colleagues drilled out four cores from the sediment around the present-day peninsula of Tyre, now called Soûr. (See map of Lebanon.)
By studying the layering of soils inside the cores, the scientists were able to piece together the last 10,000 years of coastal activity in the region.
The researchers used a computer model to process their soil data and reconstruct tidal and current patterns.
"The computer model showed that the island of Tyre acted as a natural coastal barrier to the wind and swell [coming off the Mediterranean Sea]," Marriner explained.
Beginning in the Late Bronze Age about 3,000 years ago, an increase in deforestation and farming on the island caused more sediment to flow into the sea, he explained.
The geological cores show that along the sheltered, leeward side of the island, this sediment collected together and formed a spit.
The new layering of sediment was also enhanced by a slowdown in sea-level rise that began around 4000 B.C.
By the time Alexander arrived, the sandbar extended almost all the way to the mainland, submerged under 3.3 to 6.5 feet (1 to 2 meters) of water.
"[The formation] would probably have been known to sailors, for whom it might have hindered navigation," Marriner said.
Using the sandbar as a foundation, Alexander's engineers piled up timber, stone, and rubble to construct a causeway.
"It would have been very difficult, as they only had access from one shore and would have had to build out incrementally from the mainland," said Gordon Masterton, former president of Britain's Institution of Civil Engineers, who was not involved in the new study.
"It would have been very unusual to build something like this at this time."
Nonetheless, Alexander persevered, and after a siege lasting seven months, he marched his army into the island city.
Alexander's Sandy Legacy
By the time Alexander's army founded Alexandria in Egypt the following year, it had gotten its causeway-building skills down to a fine art, Marriner added.
"His engineers probably benefited from the savoir faire they had acquired just a few months earlier at Tyre to complete the Alexandria causeway," he said. That bridge connected Pharos island, once home of a great lighthouse—one of the Seven Wonders of the Ancient World—to the Egyptian mainland.
After Alexander's victory at Tyre, the causeway there irreversibly changed the flow patterns in the water surrounding the former island.
"Both north and south of this causeway, two bays were formed, which have slowly silted up, because the long-shore currents were interrupted by Alexander's causeway," said Olaf Schuiling, a geo-engineer from Utrecht University in the Netherlands.
Around 7.5 million square feet (700,000 square meters) of new land were created, he said, forming the broad peninsula that can be seen today.