SAN MARINO, Calif. -- Members of a team led by an Emmy-award winning documentary maker described Wednesday how they used radar scans from the space shuttle to unearth the lost city of Ubar -- called the 'the Atlantis of the sands' by Lawrence of Arabia -- in the nation of Oman.
Nicholas Clapp and his colleagues of adventurers, archaeolgists and radar specialists held a news conference at the Huntington Memorial Library, a day after they announced they had found the fabled Middle East city six weeks ago.
Clapp began his 10-year search for the 5,000-year-old city -- celebrated in both the Koran and 'A Thousand and One Arabian Nights' as the center of the ancient frankincense trade -- after stumbling on a book written in 1932 by the British explorer Bertram Thomas.
Although Thomas gave coordinates of a road he believed led to Ubar -- a city some believed was mythical -- previous teams of explorers had been unable to locate it.
But then Clapp read in a magazine about a special radar system that was flown on the last successful mission of the space shuttle Challenger, and approached members of the imaging team at NASA's Jet Propulsion Laboratory.
Ronald Blom, one of the JPL scientists, said that after determining Clapp and his team were serious, scientists scanned more than 50images of the area where Ubar was described by ancient maps and books as being located.
'The key clues were the old caravan routes,' Clapp said, referring to the series of submerged desert roads carved out by teams of hundreds of thousands of camels that converged on a single site.
'As little as six weeks ago, we were on the brink of total failure.
But then Clapp and his team began gingerly digging at the site where the carvan routes converged -- and within days found walls of the ancient city 'within a couple of feet' below the surface.
The digging led to the remains of an eight-sided structure, a fortress with 10 foot to 12 foot walls 2 feet thick and 60 feet long, that is believed to have served as the home of the king at the center of what was the tent city of Ubar.
Clapp said the digging is continuing, and his team has applied for a five-year excavation permit from the nation of Oman. The bottom of the city, he said, is believed to reach 30 feet below ground.
Clapp said the search team has identified the city through pottery that has been unearthed, but he acknowleged archeologists will not be '100 percent sure' it is Ubar until inscriptions are analyzed.
Remains of bodies, he said, would be at the bottom of the city.
Called 'the Atlantis of the sands,' by T.E. Lawrence, better known as Lawrence of Arabia, Ubar was a thriving trading capital for frankincense, the highly valuable resin used in medicines, perfumes and cremations that was second in value only to gold in ancient times.
Its rulers became wealthy, and -- according to Islamic legend -- so wicked that God allowed the city to be swallowed up by the desert.
But the search team has determined the city was unwittingly constructed over a large limestone cavern until its weight caused the cavern to collapse in a massive sinkhole, destroying much of the city and causing the rest to be abandoned.
Previous researchers attempted to locate Ubar, with Thomas, apparently coming close about 60 years ago. At the time he observed the ruins of a 'rude fort' but judged it to be a few hundred, not thousand, years old.
Clapp said Thomas actually stood on top of the city, not knowing it was below his feet.
Previous search expeditions, Clapp surmised, were frustrated because of the undistinguished typography of the area, known as the Empty Quarter because it is so barren, and ambiguous descriptions in ancient maps and books.
One book said the 'Clues are so diverse, pick a place in Arabia and it's there,' noted Clapp, who did much of his research at the Huntington Memorial Library and expects his documentary on the lost city to be completed by Christmas.
Pointing to a copy of 'The Book of Imaginary Places' -- which includes Ubar -- Clapp quipped, 'It's going to have to be revised.'