Aug. 8, 2005 �?Plato's account of how the fabled city of Atlantis sank below the surface of the ocean does have scientific grounding, according to a seafloor survey of an island west of the Straits of Gibraltar.

Marc-André Gutscher of the University of Western Brittany in Plouzané, France, performed a detailed mapping of the seafloor on Spartel Island, already proposed as a candidate for the origin of the Atlantis legend in 2001 by French geologist Jacques Collina-Girard.

Lying 60 meters beneath the surface in the Gulf of Cadiz, the island is right "in front of the Pillars of Hercules," or the Straits of Gibraltar, as stated by Plato.

Analysis of sedimentary deposits revealed a large earthquake and a tsunami hit the island about 12,000 years ago, roughly the time indicated in the Greek philosopher's writings for the destruction of the city, Gutscher reports in the current issue of Geology.

"Geological records revealed that in the geographic region chosen by Plato for his narrative, there are recurrent great earthquakes (magnitude 8.5-9) which create enormous tsunamis, with waves 5-15 meters in height. One such catastrophic event occurred around 10,000 B.C.," Gutscher told Discovery News.

Even though explorers have searched for the sunken island in no less than 40 different places, no evidence of Atlantis has ever been found. Every clue about the fabled island goes back to Plato's account, written in about 400 B.C.

The philosopher claimed that two centuries earlier, Egyptian priests had told the Greek statesman Solon of a flourishing civilization outside "the pillars of Hercules."

When the people of Atlantis became wicked and decadent, the gods punished them by sending "violent earthquakes and floods."

"The power came forth out the Atlantic Ocean ... In a single day and night of misfortune ... the island of Atlantis disappeared in the depths of the sea," wrote Plato.

According to Gutscher, the type of destruction described by Plato is a very accurate description of a "sudden, catastrophic destruction associated with a great earthquake," like the famous Great Lisbon earthquake which ravaged the southern Iberian region in 1755, with associated tsunami heights reaching 10 meters (30 feet).

Evidence of Earthquakes
Indeed, sedimentary records revealed that catastrophic events like the 1755 Lisbon earthquake occur every 1,500-2,000 years in the Gulf of Cadiz.

An unusually thick turbidite, a thick, coarse-grained deposit resulting from sand and mud shaken up by underwater avalanches, was dated to around 10,000 B.C., around the same time as Plato's account.

Layers of turbidite also revealed that eight earthquakes occurred in the area after Atlantis sunk.

Each earthquake would have resulted in a drop of the sea floor by several meters, making Spartel higher by 40 meters (120 feet) by 12,000 years ago. The island could have measured five by two kilometers (three by one miles).

"If inhabited, it would have probably been by simple fishermen, certainly not the advanced Bronze Age culture described by Plato," Gutscher.

"Atlantis is a myth," Christos Doumas, Director of Akrotiri Excavations in Santorini, summarized at the conference on Atlantis on Milos Island, Greece, last month.

The conference highlighted 24 criteria that a geographical area must satisfy in order to qualify as a site where Atlantis could have existed.

Among several other oddities, the island must have sheltered a literate population with metallurgical and navigational skills, hot springs, northerly winds, elephants, enough people for an army of 10,000 chariots and 1,200 ships, and a ritual of bull sacrifice.

"No single proposed location in the world satisfies all these 24 criteria. At least the Spartel hypothesis offers a geologically plausible scenario for the type of catastrophic destruction described by Plato in this region of the world," Gutscher said.