Images made using lidar technology reveal previously unknown ancient Maya settlements with houses, temples, forts, ditches, moats and roads.Credit Luke Auld-Thomas and Marcello A. Canuto/PACUNAM
Hidden pyramids and massive fortresses in the jungle. Farms and canals scattered across swamplands. Highways traversing thickets of rain forest. These are among more than 61,000 ancient Mayan structures swallowed by overgrowth in the tropical lowlands of Guatemala that archaeologists have finally uncovered using a laser mapping technology called lidar.
The discoveries, published Thursday in Science, provide a snapshot of how the ancient Maya altered the landscape around them for more than 2,500 years from about 1000 B.C. to 1500 A.D., and may change what archaeologists thought they knew about aspects of the ancient society’s population size, agricultural practices and conflicts between warring dynasties.
The ancient Maya flourished in what is today southern Mexico, Guatemala, Belize and western Honduras. They left behind a rich written history painted and inscribed on wood, stone and ceramics. Detailed in their intricate hieroglyphics were tales of kings, queens and war.
“You’re looking at a series of kingdoms all involved in this ‘Game of Thrones’ political story where they are marrying, fighting, killing each other and backstabbing,” said Thomas Garrison, an archaeologist at Ithaca College and an author of the paper. “Lidar reveals the stage in which these dramas recorded in texts played out.”
Lidar is similar to sonar or radar, but it uses bursts of laser light to map an area.
In 2016, Juan Fernández-Díaz, a senior researcher at the National Center for Airborne Laser Mapping at the University of Houston, and his team flew over more than 800 square miles of forest in northern Guatemala in an airplane equipped with lidar. The plane was about 2,000 feet above the jungle canopy, and for every second they flew the lidar sent about half a million laser pulses.
“It’s basically like mowing the lawn. It’s going back and forth, flying very parallel lines along the jungle,” said Dr. Fernández-Díaz.
The 3-D map they made revealed new settlements with houses and temples, defensive fortifications like ditches and moats, as well as agricultural terraces and roads.
“My jaw dropped many times as I opened these images,” said Francisco Estrada-Belli, an archaeologist from Tulane University in New Orleans.
For him, the biggest surprise was uncovering vast areas of wetlands filled with channels and canals. “All of these hundreds of square kilometers of what we thought were unusable swamp were actually some of the most productive farmland.”
He said when the Maya were there, their farms probably resembled what we see in present-day Southeast Asia.
The team, whose work was funded by PACUNAM, a foundation that works to preserve Maya cultural heritage, had announced their discoveries in February through National Geographic that they had found the ruins, and have now completed their analysis.
“This is the largest survey of its kind in Mesoamerica to date,” said Marcello Canuto, an archaeologist also from Tulane University.
From the data, the team estimates there may have been about 7 to 11 million people living in the central Maya Lowlands during what was known as the Late Classic Period, which lasted from about 650 A.D. to about 800 A.D.
A lidar image of the Maya settlement Naachtun, where yellow dots and red patches represent buildings and causeways are marked in gray.Credit Luke Auld-Thomas and Marcello A. Canuto/PACUNAM
“When you’re talking about three to four times more people than you previously thought, you have to reconsider how they fed themselves, how they got along and how they handled being overcrowded,” Dr. Garrison said.
After constructing their map, members of the team revisited parts of the jungle that they had previously studied in order to verify that the structures they identified with lidar actually existed. Dr. Canuto discovered a road that he said he couldn’t believe he had missed previously.
“I went there immediately and was like ‘Oh my God, there it is!’ ’’ he said, “And then I walked on it.”
For Dr. Garrison, using the lidar map revealed that only about a hundred feet from where he had once toiled in the jungle doing research there was a fortress concealed by the foliage.
“The power of lidar first hit me in the imagery,” he said. “But taking it into the normal world of fieldwork was mind-blowing.”
