Previously unknown

Peru: 300 new Nazca images discovered with the help of AI

Some of the more than 300 newly discovered Nazca images.

(Bild: © PNAS/Sakai et al. (CC BY-NC-ND 4.0))

The Nazca Lines in Peru are world-famous - now a team of researchers has used artificial intelligence (AI) to discover and document 303 additional, barely recognizable and previously unknown figurative images in the desert near Nazca.

It took almost a century to discover 403 figurative geoglyphs known as the Nazca Lines. Now, thanks to the use of AI, researchers have succeeded in almost doubling the number of figurative images within a short space of time, scientists report in the Proceedings of the National Academy of Sciences (PNAS).

Even with limited training examples, the AI has proven to be effective in recognizing smaller relief-like geoglyphs, which are very difficult to recognize in contrast to the huge line-like sharps in the Peruvian highlands, according to the researchers.

What are geoglyphs?

Geoglyphs are large-scale figurative representations formed on the ground in lines or formed by roads and paths. This is why they are often also called earth or ground drawings. These often extend over several hundred meters and are often only visible from the air due to their large size.

Aerial photographs analyzed with the help of AI
For their study, Masato Sakai from Yamagata University in Japan and his colleagues used an AI system adapted to the analysis of aerial photographs. Using sections of known Nazca geoglyphs, they trained the system to recognize the typical lines in the desert floor. The search focused on the smaller Nazca geoglyphs of the so-called relief type, which are on average only around ten meters in size.

Of the1300 geoglyph candidates identified thanks to AI, the researchers have already examined some of them on site and discovered no fewer than 303 figurative relief images. Based on the results so far, they assume that they will find many more - more than 200.

(Bild: © PNAS/Sakai et al. (CC BY-NC-ND 4.0))

Distribution of the figurative carvings analyzed
The improved representation of the figurative geoglyphs enables us to analyze the motifs and their distribution in the Nazca pampas, the researchers report. With the help of AI, it has been possible to determine that the relief type's figurative images mainly (in 81.6 percent of cases) depict human motifs or things that have been altered by humans, such as domesticated animals and decapitated heads.

They are usually located within sight (on average 43 meters away) of ancient paths that crisscross the Nazca pampas and were probably erected and viewed by individuals or small groups, report the scientists led by Masato Sakai.

In contrast, the huge, line-shaped scarps mainly depict wild animals (in 64 percent of cases), they say. They are located an average of 34 meters away from the elaborate linear/trapezoidal geoglyph network, which suggests that they were probably erected and used for ritual activities on a communal level, according to the researchers.

Usually only visible from a great distance
The Paracus and Nazca cultures are thought to be the originators of the lines. The scarified images were created between 500 and 500 AD. Due to their enormous size, they can only be seen from a great distance, from the surrounding hills or from airplanes.

It is still a great mystery as to why they were created. It is possible that they were used for ceremonial purposes. In 1994, the UN cultural organization UNESCO declared the Nazca Lines a World Heritage Site.