Nicholas Clapp, 89, Dies; ‘Real-Life Indiana Jones’ Pursued a Lost City

Nicholas Clapp, a documentary filmmaker and adventurer who was called “a real-life Indiana Jones” for his consuming but inconclusive quest to find a lost city of ancient Arabia known as Atlantis of the Sands, died on July 30 at his home in Borrego Springs, Calif., northeast of San Diego. He was 89.

His daughter Cristina Clapp said the cause was complications of a stroke.

In 1981, Mr. Clapp wandered into a Los Angeles bookshop looking for a reason to return to the Arabian desert, where he had recently worked on a documentary in Oman about an endangered antelope species called the oryx.

Browsing, he came across a 1932 travelogue by the British explorer Bertram Thomas, “Arabian Felix: Across the Empty Quarter of Arabia.” The book told of Bedouin guides mentioning a road to a legendary city called Ubar. (Although T.E. Lawrence, the British Army officer and archaeologist, often gets the credit, Mr. Thomas is considered by many to be the first to have referred to Ubar as Atlantis of the Sands.)

The Quran refers to a mythic place named Iram, which Mr. Clapp believed was “one and the same” as Ubar, though there was not a scholarly consensus.

It described Iram as a “many-columned city” whose “like has not been built upon the entire land” — a place that was gloriously rich but sinful and had been destroyed by divine wrath. “The Arabian Nights” also mentions the columns of Iram and the city’s calamitous destruction.

For decades, Western adventurers had sought in vain to find the fabled city. It was believed to have been a trading post along camel routes that, thousands of years earlier, had been an avenue for transporting frankincense, whose resin was prized as a fragrance and a substance used in embalming.

Mr. Clapp believed that he possessed one counterintuitive advantage in the quest to find Ubar: He was not a professional archaeologist.

“There are no reputations at stake, no colleagues looking over your shoulder,” he would tell The Los Angeles Times years later. “That freed me to perhaps do things others wouldn’t do.”

To be sure, he needed a way to see beneath the sand that had blown across the southern Arabian Peninsula over the centuries.

He had read a newspaper article about an airborne radar system that had helped find Mayan ruins beneath a jungle canopy, and in 1983 he phoned the NASA Jet Propulsion Laboratory and spoke with Ronald G. Blom, a geologist and specialist in remote imaging.

As Dr. Blom recalled to The New York Times years later, Mr. Clapp asked, “If a city was buried in the desert, could you see it by this radar?”

In 1981, an imaging-radar system aboard the space shuttle Columbia had found previously undetected riverbeds beneath the sands of Egypt. Dr. Blom put Mr. Clapp in touch with Charles Elachi, who had developed the shuttle’s imaging-radar system, which was to be used next on a 1984 flight of the shuttle Challenger.

Mr. Clapp asked Dr. Elachi, “Could the spacecraft be used to find a lost city?”

Dr. Elachi agreed to try, and the Challenger made two passes over a desert in southern Oman known as the Empty Quarter. The Challenger’s imaging radar was combined with satellite mapping that used near-infrared imaging to reveal rock and soil conditions invisible to the human eye.

No buried ruins were found. But the space imaging did detect miles of tracks of ancient caravan routes, converging on the remnants of a stone fort at a water well known as Shisr.

To investigate the site, Mr. Clapp assembled a team that included Dr. Blom; Ranulph Fiennes, a British explorer with ties to the sultan of Oman; Alan Jutzi, a curator of rare books at the Huntington Library; Juris Zarins, an archaeologist who was a specialist on the Middle East; and George Hedges, a Los Angeles lawyer with a background in classical archaeology.

A 1990 ground reconnaissance mission to Shisr required crossing forbidding terrain that was populated, in Mr. Clapp’s telling, by poisonous snakes, giant spiders and armed herdsmen who were infuriated that the team’s helicopter scared their goats. The trip turned up artifacts indicating that the site had been part of the frankincense trade route.

Excavation there during a second trip, beginning in November 1991, uncovered the ruins of a buried city, octagonal in shape, with eight towers, adjoining walls that had once stood roughly 30 feet high, and pottery that was more than 4,000 years old. The structures had been built around a water reservoir in a limestone cavern and were believed to have collapsed from their own weight, perhaps between A.D. 300 and A.D. 500.

In a front-page article on Feb. 5, 1992, The Times reported that the explorers and archaeologists were “virtually sure” that they had found Ubar, depicted on Ptolemy’s maps as Omanum Emporium. But this would not end the debate.

Nicholas Roger Clapp was born on May 1, 1936, in Providence, R.I. His father, Roger Tillinghast Clapp, was a lawyer; his mother, Helen (MacRae) Clapp, volunteered at the Providence Art Club.

Nicholas graduated from Brown University in 1957 with a bachelor’s degree in American literature and then served in the Army Reserve. In 1962, he earned a master’s degree from the University of Southern California’s School of Cinematic Arts.

In addition to his daughter Cristina, from his marriage to Kathryn Kelly, which ended in divorce in 2002, Mr. Clapp is survived by his wife, Bonnie (Loizos) Clapp, whom he married in 2004, and another daughter, Jennifer Clapp, from his first marriage.

Mr. Clapp was involved in the making of two Oscar-nominated documentaries. He was an executive producer of “Journey to the Outer Limits” (1973), about Outward Bound students climbing in the Andes, which was also nominated for, and won, an Emmy Award; and he was a production manager on “The Incredible Machine” (1975), about the workings of the human body.

He also directed a 1996 documentary, “The Lost City of Arabia,” for the PBS series “Nova,” and wrote a 1998 book, “The Road to Ubar: Finding the Atlantis of the Sands.” In an article after the book was published, The Los Angeles Times called him “a real-life Indiana Jones.”

In that book, he said that the evidence suggested “a convincing match” for the lost city. But the truth remains uncertain.

Dr. Zarins, the chief archaeologist of the Clapp-led expedition, told The Times in 1992, “There doesn’t seem to be much question that we have discovered Omanum Emporium.”

But by 1997, he seemed to be having second thoughts: He wrote in Archaeology magazine, “It would appear that the city of Ubar was an ‘Arabian Nights’ fantasy.”

The site was considered archaeologically significant, but some scholars said that it was too small to have been the city of legend, and that Ubar may have been a region or a tribe instead of a city. Some archaeologists believe that Atlantis of the Sands may have been in southern Jordan.

“Taking a flinty-eyed look at it, we just don’t know,” Dr. Blom said of Ubar in a NASA interview in 2017. “Nobody ever found a sign that said, ‘The Ubar Chamber of Commerce welcomes you.’”