Some 2,000 years ago, the ancient people of southern Peru created hundreds of enormous drawings in the soil, which are known today as the Nazca Lines.

Now, scientists have used advanced techniques to discover 143 previously unknown “geoglyphs,” the term for these etched figures, within the Nazca region. One newly found geoglyph, which appears to represent a humanoid figure, was even identified by an AI model, according to the recent announcement of the discovery.

Satellite image of humanoid geoglyph (left) and enhancement (right). Image: Yamagata University/IBM Japan

A team led by Masato Sakai, a cultural anthropologist at Yamagata University in Japan, has spent years hunting for geoglyphs during onsite expeditions, while also scouring high-resolution images of the Nazca Lines taken from space.

These efforts led to the detection of the new figures, which range from roughly five to 100 meters in length. Much like the known Nazca drawings, the geoglyphs discovered by Sakai’s team depict a wide range of living things and objects, including people, birds, monkeys, fish, reptiles, and more abstract designs. The drawings were made by the ancient culture by removing the rocky black topsoil, which revealed light-colored sand underneath.

Sakai and his colleagues noted that the larger geoglyphs, labelled as Type A, tended to represent animals. These figures stretch out for at least 50 meters, and generally appeared later in the timeline of Nazca civilization, between 100 and 300 CE.

The smaller geoglyphs, called Type B, were typically a few centuries older than their larger counterparts, dating back to about 100 BCE to 100 CE.

Type B figures are often located on slopes and paths, so Sakai’s team thinks they may have been designed as landmarks to help guide people. The Type A figures, in contrast, are often littered with pottery shards, suggesting that they were sites of ritual ceremonies that involved breaking objects.

One of the Type B figures—the aforementioned humanoid—was discovered with the help of IBM Watson Machine Learning Community Edition, a deep learning system. Sakai’s team worked with the IBM Thomas J. Watson Research Center in the US to train the AI to scan satellite imagery of the region and flag promising sites for unfound geoglyphs.

Processed image of a two-headed snake geoglyph. Image: Yamagata University/IBM Japan

The platform spotted potential in an area in the western part of the Nazca Lines, and Sakai’s team was able to find the humanoid glyph, which is only five meters in length. This marks the first time an AI has pinpointed the location of a new geoglyph in the Nazca region, but the researchers plan to continue using AI to find, map, and categorize new figures.

This effort is important not only for understanding the vast extent and complexity of the Nazca Lines, but also to help preserve them for future generations.