"To uncover the latest batch of ruins, researchers used geomagnetic mapping, a technique that can differentiate between rock types to detect granite or limestone artifacts beneath layers of sediment. These techniques were instrumental in finding the completely buried ruins of Herakleion, Nur said.
"There was nothing on the surface. Just by diving we would never have discovered this, he said."
Archaeologists have always wondered what happened to Menouthis and Herakleion, prominent Mediterranean coast cities during the Hellenistic period that disappeared into the sea more than 1,000 years ago. How did they come to be wiped off the map? An earthquake? Rising sea levels? No one knew.
Now, an international team of archaeologists, historians and geophysicists believes it has the answers. On June 3, Franck Goddio, president of the Paris-based European Institute of Marine Archeology, in conjunction with the Supreme Council for Egyptian Antiquities, proudly announced the discovery of the two lost cities in Abu Qir Bay, east of Alexandria.
Though waiting to confirm details, the researchers are excited. "We don't know the exact dates of these cities, but we are mapping each structure one by one and we are building an impressive collection," Goddio said.
The sunken cities of Menouthis and Herakleion, also known as Thonis, they believe, were discovered so recently that little excavation has yet been done. Located east of present-day Abu Qir, these cities were wealthy trading ports during the Pharaonic period due to their favorable positions along the now-vanished Canopic branch of the Nile, which ran to the east of the river's present course.
Researchers found two different sites: the first, about two kilometers from land, holds the remains of Menouthis and Canopus (a city discovered previously that hasn't been excavated yet) and covers a 700 by 500 meter area. The second site, whose size is unknown, was found only a few weeks ago and the team believes it is the ruins of Herakleion.
Mentioned in accounts by Herodotus, Strabo and other classical writers, the cities also appear in stories of the Trojan Wars, but researchers had never been able to confirm their existence. Even with the discovery, many questions remain.
"The question now is, why did these cities sink?" said Goddio. Herakleion might offer the best answers: completely buried beneath layers of sediment and mud, it was protected from the salt water and currents, so the ruined houses, temples, giant statues and a port infrastructure were thus preserved.
"This city is absolutely untouched," Goddio said. "Everything is in its original position."
The cities, each of which had a population of three to five thousand people, went into decline following the founding of Alexandria in 331 BC, which quickly became the regional trading powerhouse.
However, they remained important centers of pilgrimage for the Isis and Serapis cults (cult adherents continued to believe in traditional fertility deities like Isis and Osiris long after the introduction of Christianity) until the 6th century AD, according to Manfred Clauss, a Professor of Ancient History at Johann Wolfgang Goethe University in Frankfurt.
"[This area] was famous for its cults, Isis temples and Serapis temples – [the area] from here to Alexandria was filled with pilgrimage sites," he said.
Then something happened. The cities just disappeared, sometime between the 8th and 10th centuries AD.
Amos Nur, chairman of the Geophysics Department at Stanford University in California, thinks he knows the answer: earthquakes. There is evidence of major earthquakes in the 3rd, 4th and 8th centuries AD, he said, but whether they destroyed the cities in stages or in one giant cataclysm that sunk everything is still unknown.
"The guess right now is earthquakes, because we know earthquakes happened here, but we still need to sort it out," he said. "When did they occur, and where is the fault [line] that's responsible for this?"
A rise in the Mediterranean's water level is another possible cause for the cities' disappearance.
The team also presented a number of sculpture fragments from the Pharaonic and Hellenistic periods, as well as gold coins from the Islamic and Byzantine eras, all recently retrieved from Abu Qir. The finds included the head of a 25th Dynasty Ethiopian Pharaoh from the 7th or 8th century BC and part of a tablet covered in classical astrological inscriptions. Researchers also found a massive head of Serapis from the Greco-Roman period, believed to be from a cult temple in Menouthis.
"I think it is the main discovery in the category of sculpture," said Zsolt Kiss, an art and archaeology expert at the Polish Academy of Science in Warsaw.
High winds and rough seas ruined plans to ferry journalists out to a spot in the bay to watch a statue being pulled from the water. Instead, the statue, a headless Isis in smooth black granite, about 1.5 meters high, had been salvaged earlier in the day and was unveiled in Abu Qir Harbor.
Researchers said the sculpture had only been discovered a few days before, but it was almost certainly from an Isis cult temple in Menouthis. Goddio estimated that the statue was 1,200 years old.
To uncover the latest batch of ruins, researchers used geomagnetic mapping, a technique that can differentiate between rock types to detect granite or limestone artifacts beneath layers of sediment. These techniques were instrumental in finding the completely buried ruins of Herakleion, Nur said.
"There was nothing on the surface. Just by diving we would never have discovered this," he said.
Seismic measurement techniques and acoustic photography (a type of sonar) were used as well, Nur said.
Minister of Culture Farouk Hosni, scheduled to speak at the conference, was unable to attend, the state-owned Al Gomhuriya newspaper reported on June 4. Widespread speculation followed that Hosni, still reeling from the controversies surrounding Syrian writer Haydar Haydar's novel A Banquet for Seaweed and alleged gifts of antiquities to foreign diplomats, did not want to face the press.
Goddio has been exploring the waters off Alexandria since 1996. Previous finds have included L'Orient, Napoleon's flagship, destroyed by the British fleet in the Battle of the Nile in 1798, and Cleopatra's Royal Quarters.
After four years of excavation, this is just the beginning, according to Gaballa Ali Gaballa, chairman of the Supreme Council for Egyptian Antiquities.
"This is just a glimpse of what the waters of Abu Qir are holding," he said. "I don't think I'm exaggerating when I say we have work here for the next 50 years."