AI Research Uncovers Hundreds of ‘Nazca Lines’ Geoglyphs

It took researchers a century to discover 430 geoglyphs, some enormous, scattered across the ground in the Nazca region of Peru. Now, a team of scientists has nearly doubled the number of known geoglyphs in just six months, using an AI-powered approach to uncover some of the more elusive figures.

The Nazca Lines refer to a collection of these geoglyphs in the Nazca Pampa; approximately between 200 BC and 500 ADlocal groups removed dark rocks from the surface of the arid lands to reveal the white sandy soil beneath. They did this on smaller scales, but also on glyphs so large that they could only be properly seen from the air.

The lines are old but were rediscovered in bulk in the 20th century; yet some have remained under the radar. A cat geoglyph (i.e. depicting a cat) was discovered in 2020found on a hillside in the area. Last year, two members of the final team four new geoglyphs identified using an object detection algorithm, but they didn’t conduct a more comprehensive survey. Now, the larger team has done just that and has been rewarded for their AI-powered efforts.

As the team wrote in the resulting paper, the final model “focuses on relief-type geoglyphs, which are small and difficult to identify, as the distribution of large line-type figurative geoglyphs is known from previous (manual) aerial studies,” It was published earlier this week Proceedings of the National Academy of Sciences (PNAS).

While convolutional neural networks are typically trained on tens of thousands of images, the latest team’s model was trained on images of just a few hundred known geoglyphs. IBM’s geospatial platform PAIRS first cleaned the data before feeding it into the model, which then divided the Nazca Pampa into a grid and highlighted sections that appeared to contain a glyph. The identified candidate glyphs were then passed on to human archaeologists, who sorted the wheat from the chaff.

Even without a lot of data to train their model, the team found that their AI approach effectively identified geoglyphs. It suggested 1,309 potential glyphs, and over the course of the next two months of work, the team identified 303 figurative geoglyphs and 42 newly identified geometric glyphs.

The team also detected distinct patterns in what the larger and smaller glyphs depicted. Monumental glyphs generally depicted animals and plants, while relief-type geoglyphs depicted humans, decapitated heads, and domesticated camelids. The smaller geoglyphs are located an average of about 141 feet (43 meters) away from the ancient pathways that crisscross the Nazca Pampa region, which were likely used to display the glyphs.

The newly discovered small geoglyphs include 47 depicting wildlife, including figures of birds, cats, snakes, monkeys, foxes, killer whales and fish.

Big geospatial data technologies and data mining are accelerating the pace of discovery in aerial archaeology, the team wrote in their paper. “As such, AI may be on the verge of leading a revolution in archaeological discovery, much like aerial imaging has revolutionized the field.”