With AI and drones, hundreds of Nazca lines are discovered in the Peruvian desert

The Nazca Lines, excavated in an arid pampa in southern Peru, are one of the most baffling mysteries in archaeology.

On the coastal desert floor, the shallow marks look like simple grooves.

But from the air, hundreds of meters high, they transform into trapezoids, spirals and zigzags in some places, and into stylized hummingbirds and spiders in others.

There’s even a cat with a fish tail.

Thousands of lines jump cliffs and cross ravines without changing course; The longest is straight like the trajectory of a bullet and extends over 24 kilometers.

In the mid-1920s, a Peruvian scientist discovered the enormous incisions while hiking in the Nazca foothills.

Over the next decade, commercial pilots flying over the region revealed the enormity of the works of art, believed to have been created between the 200 BC and 700 AD. for a civilization before the incas.

“It has taken almost a century to discover a total of 430 figurative geoglyphs,” said Masato Sakai, an archaeologist at the Yamagata UniversityJapan, which has been studying the lines for 30 years.

Sakai is the lead author of a study published in September in the journal Proceedings of the National Academy of Sciences which found 303 previously unknown geoglyphs in just six months, almost double the number that had been mapped until 2020.

The researchers used artificial intelligence along with low-flying drones and covered about 629 square kilometers.

Their findings also provided insight into the enigmatic purpose of symbols.

The newly found images—an average of 30 feet wide—could have been detected on previous flybys if pilots had known where to look.

But the pampa is so immense that “finding the needle in the haystack is practically impossible without the help of the automation”said Marcus Freitag, an IBM physicist who collaborated on the project.

To identify the new geoglyphs, smaller than the previous ones, the researchers used an application capable of discerning the contours from aerial photographs, no matter how faint they were.

“The artificial intelligence was able to remove 98 percent of the images,” Freitag said.

“Now human experts only have to confirm or reject plausible candidates.”

That 2 percent marked by artificial intelligence amounted to 47,410 potential sites on the desert plain.

Sakai’s team then pored over the high-resolution photos and narrowed the list down to 1,309 candidates.

“They were then classified into three groups based on their potential, allowing us to predict the likelihood that they were real geoglyphs before visiting them,” Sakai explained.

Two years ago, researchers began exploring the most promising sites on foot and with drones, eventually “field-checking” 303 geoglyphs.

Among the performances were plants, people, snakes, monkeys, cats, parrots, llamas and a creepy painting of a knife-wielding orca and cutting off a human head.

Of the new figures, 244 were suggested by the technology, while the remaining 59 were identified during field work without help from AI.

The Nazca carved the designs into the earth by scraping the surface composed of rust-colored pebbles to reveal the yellow-gray subsoil.

Little is known about this mysterious culture, which left no written records.

Apart from the engravings, almost all that exists of the civilization are pieces of pottery and a ingenious irrigation network that still works.

The ancient geoglyphs have attracted theories ranging from the religious (they were tributes to powerful gods of the mountains and fertility) to the environmental (they were astronomical guides to predict the infrequent rains in the nearby Andes) or the fantastic (they were landing strips and parking lots for extraterrestrial ships).

Sakai said the geoglyphs were drawn near pilgrimage routes to temples, implying that they functioned as sacred spaces for community rituals, and could be considered planned public architecture.

The newly discovered geoglyphs are found primarily along a network of trails that meandered across the pampas.

Most likely, they were performed by individuals and small groups to share information about rituals and animal husbandry.

Although the archaeological site is a restricted and protected area, the lines have been threatened by occasional acts of vandalism.

In 2014, Greenpeace activists left footprints near the colossal hummingbird geoglyph during a protest aimed at delegates at the United Nations climate negotiations in Lima.

Four years later, three geoglyphs were damaged when a truck driver apparently avoided a toll by driving a trailer through the sand.

Sakai noted that marks in places exposed to flash floods and landslides are especially vulnerable.

When these geoglyphs “are partially destroyed by water, it is difficult to determine their original shape,” he explained.

Of the original 1,309 candidates, Sakai estimates that there are at least another 500 undetected figures.

“I think more surprising facts will emerge,” he said.