Thousands of Mayan ruins have been detected in the Guatemalan jungle thanks to Lidar technology, revealing the unsuspected magnitude of interconnections between cities.
The discovery is exceptional. Thousands of unknown Mayan structures and buildings, hidden under the canopy for centuries, have just been spotted by archaeologists.
These large-scale constructions include pyramids, palaces, ceremonial centers, but also less spectacular works such as cultivated plots or dwellings.
All are located in the jungle of northern Guatemala, and it is thanks to the use of Lidar (Light Detection And Ranging), an airborne remote sensing system, that they have been identified as part of a consortium created under the aegis of the PACUNAM Foundation.
This laser system, coupled with a high-precision GPS, makes it possible to detect all the details on the ground, including under a thick canopy. It had been used successfully on the Angkor site in Cambodia. The set of points recorded during the overflight is then filtered using powerful algorithms to make a digital model of the terrain via 3D photogrammetric renditions. The Lidar thus allows a kind of digital virtual deforestation that reveals all the topographical details present over vast areas.
This digital mapping extends here over 2100 km2 divided into nine sectors north of Peten, particularly in the „Maya Biosphere Reserve“, established in 1990 to protect the largest area of remaining tropical forests in Central America.
„Lidar is a relatively new airborne remote sensing technology that allows detailed mapping of the Earth’s surface to a very fine scale and is far superior to previous forms of satellite or airborne mapping in that Lidar can penetrate dense vegetation and is ideal for the Mayan lowlands, where jungle vegetation prevents traditional mapping, „said Michael E. Smith, Mesoamerican Archeology Specialist at the University of Arizona (USA).
Researchers have discovered the existence of several urban centers, sophisticated irrigation systems, and achievements such as raised roadways that can be used during the rainy season. They have also been able to point more than 60,000 individual structures, whether they are isolated houses, reservoirs or fortifications. A 30m-high pyramid – previously identified as a hill – has even been detected in Tikal, yet one of the most studied and visited cities in the Mayan world!
„In some cases, known urban centers were 40 times larger than existing maps, including several monumental complexes previously considered separate sites,“ said Francisco-Estrada Belli of Tulane University in New Orleans (USA), involved in the study.
One of the most important information provided by this work is the unknown interconnection existing between different Mayan cities, in this area well known to archaeologists for its architectural richness, especially in the so-called classical period (250 to 900 AD). „The Mayan Biosphere Reserve“ is indeed famous for a strong concentration of ancient cities, including Tikal, abandoned in the tenth century.
Two other 3D views of Tikal, without forest cover, obtained from Lidar survey analyzes. © PACUNAM
„Do not forget that on every image obtained, there is a millennium and a half of concentrated human occupation!“, Recalls Dominique Michelet, director of research emeritus at the Archeology Laboratory of the Americas (UMR 8096) at the CNRS, involved in the Naachtun project.
Also, for him, no question of hasty interpretations. „Moving from these 3D renditions to extrapolations on occupancy figures by the Mayan populations, evoking millions of individuals as we have read, is simply breathtaking,“ the archaeologist continued.
What Michael E. Smith confirms in his own way: „The Lidar will certainly help revolutionize the study of the colonization and demography of the Maya, but we are only at the preliminary stage of establishing beautiful maps. 3D … Not yet the one to have solid results on the architectures, the demography or the functioning of these companies „. It will therefore be necessary to wait for finer analyzes to obtain serious estimates of the population. And these steps are just beginning for the Mayan lowlands, where the entire occupation pattern is now to be reviewed.
The Naachtun project
„The results of the exploitation of Lidar imagery on the Guatemala region at the heart of our activities were a real shock,“ admits Philippe Nondeneo, director of the Franco-Guatemalan project Naachtun, named after an important Mayan center located in the Peten region and the El Mirador basin, which the researcher has been studying since 2011 with Dominique Michelet.
The two researchers explain that the results delivered by Lidar technology have extended this area of investigation to 140 km2, 70 times the study area discussed so far. 12,000 structures from all periods have been identified! Either a density of occupancy greater than anything they could imagine.
Finally, only the marshy areas would be free of remains. „If we compare these results to all the Maya sites that have also been the subject of this Lidar cover, it appears that Naachtun, by its density of structures, is now comparable to the great Tikal!“