Lidar exposes remnants of an ancient civilization overgrown in the Amazon – TechCrunch

It’s Friday and the world is falling apart, so let’s take a short sanity break with some exciting news outside the realm of archaeology, where technology is enabling fascinating new discoveries. A new analysis powered by lidar of land in the Amazon Basin provided evidence of a previously unknown urban center of “breathtaking” complexity.

To be clear, this doesn’t mean ancient extraterrestrials or long-lost technology, just that it far exceeds the expected levels of organization and population that researchers considered possible for Amazonians of 1 year ago. 500 years.

“No one expected this kind of society in this region… pyramids 20 meters high,” said Heiko Prümers of the German Archaeological Institute, in a video produced by Nature. “The whole region was so densely populated in pre-Hispanic times, it’s incredible to believe. There is a new civilization, a new culture, waiting for us to study them.

Until recently, the Amazon was thought to have only smaller tribes until the arrival of Spanish and Portuguese explorers – a typically Eurocentric view increasingly challenged by new studies. In this case, Prümers was intrigued by mounds called lomas, hidden under the vegetation but suggesting something bigger. Excavations have shown that these were not dumps (as some thought) but organized areas for tombs, rites and other things indicative of a complex and hierarchical society.

But finding bumps on the ground under a rainforest canopy is far from easy, so in 2019 they set out to scan the area by helicopter, using lidar to reconstruct surface contours under the trees. . This technique has proven very successful recently, with entire Mayan cities and even a kilometer-long artificial earthwork discovered this way.

Picture credits: Prumers et al.

Lidar beams pass between leaves and branches, bouncing around to provide amazingly detailed insight into the height of the ground below. And more than ever, this data can be quickly collected and analyzed to produce an easily inspected 3D point cloud for hidden structures.

What the team found was more than a few new lomas: platforms, huge pyramids, defensive structures, reservoirs and canals and more connecting what appeared to be hundreds of settlements of varying sizes. This runs counter to assumptions that local peoples were nomadic or forage cultures, not sedentary and agricultural cultures.

Lidar imaging of features discovered in the town of Casarabe using lidar.

Lidar imaging of features discovered in the town of Casarabe using lidar. Picture credits: Prumers et al.

The Casarabe culture, as it was named following its discovery, remains for the most part a mystery. After all, its existence has only recently been confirmed – but it does provide a starting point for further investigation.

“We have to be patient and wait for further excavations at these sites to be able to explain anything of what we’re seeing right now,” Prümers said – although it’s work of a scale and duration that could l to bequeath it to his students. . “For me, having worked for the past 20, 25 years in this region, it’s a kind of dream come true! Saying at the end of my career that, yeah, we got a new culture? It’s nice, I admit.

As in many fields, technology is an enabler (Prümers estimated that it would have taken 400 years of excavation to unearth everything they found using lidar) but can never replace hard work and innovation. expertise that humans bring to the equation. You can read the full article (it’s open access) in Nature.