Space-Age Archaeology Digs In
Satellite-images help scientists find the site of an ancient city buried in the sand
LOS ANGELES — IN a downtown law office here, attorney George R. Hedges and filmmaker Nicholas Clapp are lamenting the "15 minutes of fame" that has come with their role in discovering the lost city of Ubar, "Atlantis of the sands," announced early this month.
"Now that we found it, the media have been in a feeding frenzy ever since," says Mr. Clapp, the lifelong Arabophile who had been piecing together bits of literature, scientific history, and artifacts since 1983 to find a treasure many thought did not exist. He recounts a decade of fruitless knocking on foundation doors for support in his search for the 5,000-year-old fortress city.
"Where was all the attention when we needed it?" he asks.
Now the public imagination has been captured by fables of the ruins once described in the Koran as the "city of towers" and in "Thousand & One Nights" as the center of the frankincense trade for 30 centuries.
Historians are celebrating the opening of new windows on commerce, trade, and religious ritual in the region that gave rise to Islam, Christianity, and Judaism.
Geologists and archaeologists are cheering the successful use of satellite-imaging techniques to pinpoint the area in a section of sand so remote it is known as the Rub'al Khali or "Empty Quarter."
"This is a wonderful discovery for the world of archaeology," says McGuire Gibson, an archaeologist at the University of Chicago (UC) Oriental Institute. "[The discovery] and those to come will fill in parts of the puzzle from Solomon to the Queen of Sheba. It's also nice to know the technology we are all investing in is showing fruition," says Mr. Gibson.
From a hotel in Paris, British explorer Sir Ranulf Fiennes, who co-led the expedition, explains that the discovery of Ubar will help build a more cogent tracing of the development of civilization from its origins in Mesopotamia. If the discovery proves valid, the spread of civilization to the Arab peninsula will antedate current predictions by a full 10 centuries.
"More recent frankincense routes to western Arabia are well documented," Mr. Fiennes says. "But the bigger picture of trade with the Sumerians seems to be forgotten. This will fill in the holes."
Gibson and UC colleague Tony Wilkinson say the space-imaging and ground-penetrating radar used to help find Ubar have been in common use by geologists, oil companies, and others for more than a decade. But several analysts say innovations in noise reduction, atmospheric corrections, and filtering by Jet Propulsion Laboratory (JPL) scientists were the breakthrough to the history-making find.
"Most people do these searches cookbook-style," says JPL scientist Ronald Blom, whom Clapp enlisted in 1984 to help find Ubar. "But the final souffle depends on how the cook knows to juggle the ingredients." Mr. Blom and colleague Charles Elachi collected images taken from 250 miles high by the space-shuttle Challenger on its last successful mission in 1985. They combined them with high-resolution images from French-owned satellites as well as aerial photographs.
The digital nature of satellite images allows them to be analyzed in various computer modes, says Blom. Infrared-light highlights features unseen by the naked eye because of its longer wavelengths. Despite shifting sand that covered target areas up to six feet deep, the satellite-imaging technique helped delineate roads, trails, water paths, and other features indistinguishable to ground-based explorers.
"Once you collect all the images, it's like putting together a road map," says Blom. "On the ground you would walk over them without knowing."
Fiennes says some press accounts have misreported the benefit of space technology in the Ubar find. "Satellite imaging did not locate the city itself but rather told us we had been searching in the wrong place," he says.
Crews had done preliminary excavations at about 35 sites on reconnaissance expeditions last summer. But subsequent analysis of ancient water tables, as shown by sonar, indicated that not enough water existed to support a city the size of Ubar. "The images told us the city could be found, only further to the east," he says.
Today, up to 40 volunteers continue digging at a site near a Bedouin crossroads called Shisr. Preliminary findings include a fortress ringed by eight walls, each about two feet thick, 60 feet long, and 10 feet high. At each corner stood a 30-foot tower about 10 feet in diameter. Roman, Greek, and Syrian pottery has been identified at the site.
Much of the structure has caved into a sinkhole that will require sophisticated engineering to excavate without causing further damage. The explorers have presented their findings to Sultan Qaboos of Oman and requested several more years of exploration time.
"This holds the key to the closest and earliest trade that Mesopotamia could have reached, dating back to 3,000 to 4,000 BC," says chief archaeologist Juris Zarins, speaking by phone from the Holiday Inn in Salalah, Oman, about 100 kilometers (64 miles) from the site.