In 2022, Richard D. Hansen led a team in Guatemala’s Mirador-Calakmul Karst Basin and found Mayan structures consistently spread over a 650-square-mile area (slightly larger than modern London). They identified 964 previously unknown sites aged 1000 B.C. to A.D. 150 and 110 miles of raised causeways connecting them. While it was already known that Mayan civilization was spread throughout Central America, many assumed tropical forest settlements were an obstacle to creating complex societies.
“For too long, Maya archaeologists have been blinded by the jungle,” wrote Arlen Chase, Diane Chase, and John Weishampel, in a 2010 Archaeology article.
And now, using light detection and ranging, lidar for short, developed for NASA, archaeologists are mapping more hidden ruins than ever before.
Mapping Archaeology Sites With Lidar Technology
In 1929, Charles and Anne Morrow Lindbergh assisted Carnegie Institute archaeologists with an aerial expedition over Central America. As they flew a Sikorsky S38 over Mayan ruins, the archaeologists could see their sites of interest from above for the first time and search for new ones in a matter of hours. Aerial photographs from this expedition solidified the value of viewing ruins from above.
Today, archaeologists are using a new technology to map ruins from above. But what is lidar technology? Lidar shoots lasers down from above – hitched to a drone, helicopter or plane – creating detailed digital maps. Unlike an aerial camera, the lasers fit between the leaves of the tree canopy revealing detailed maps of topography too difficult to observe with the naked eye, making it possible to map even the most forested places. Though archaeologists are better known for their work on the ground, this technology has enabled them to tell new stories of human habitation and environmental change.
With the applications of lidar at the Belize city of Caracol, researchers mapped some 500,000 acres. Perceptions of tropical forests as completely wild jungles, devoid of complex civilizations – or even the possibility of creating one in its landscape – have shaped the field’s questions for generations. The Chases’ map revealed the tallest man-made building in Belize, as well as monuments, houses, terraces, roads, causeways and highways. It would have taken a lifetime to plot these points by hand from the ground.
Ancient Life in Tropical Forests
In the big picture, this new understanding of the Americas shows that humans were not simply eking out an existence from the rainforest but thriving in it. Even in the Amazon, archaeologist Heiko Prumers last year found extensive evidence of human-modified landscapes of the Casarabe culture that represent what he calls “tropical low-density urbanism” previously not known.
Archaeologist Patrick Roberts has also written about shared connections across equatorial forests going back some 50,000 years. He has found evidence in the Amazon and Southeast Asia that nomadic people were manipulating the forest. Fossilized pollen and seeds change through time, showing evidence of controlled burns. This revealed that humans were adeptly enriching the soil to encourage the growth of preferred trees.
“The complexity involved with these systems, the thought involved that had to take place in order to properly develop these agricultural systems […] was eye opening,” says Weishampel who worked alongside the Chases.
Lidar Identifies Complex Living for Ancient Cultures
In Cambodia, lidar helped locate the ruins of the legendary city Mahendraparvata, soon to become a national park, and revealed that Angkor Wat was not an isolated ceremonial center but a sprawling metropolis the size of Berlin. In the Central African Rainforest, studies of tree species and pottery samplings are reversing the idea that it was a “green desert” making our understanding of how people have lived alongside tropical forests much more intricate and remarkable, according to Roberts.
From lasers in the sky to dirt under the microscope, today’s research is proving tropical forests were not hostile to complex culture. Terraces and canals show innovation in farming. Layers of burnt soil reveal controlled burns for forest management and use of charcoal to fertilize crops. Architectural ruins reveal much of what has been assumed untouched forest was used for suburban sprawl and farmland. And there’s still so much to research.