Vegetation is probably the world’s best secret keeper. It’s kept some of the world’s most famous archeological sites hidden from our eyes for centuries. Even now, some of the most amazing sites that have been the focus of much archeological attention, such as Guatemala’s Tikal and Mexico’s Cobá, are still 90% covered in thick jungle. Who knows what other treasures we might find in the coming years? Well, thanks to lasers, we might start finding out a little sooner than we’d hoped.
More and more archeologists across the globe are beginning to trade in their trowels for more sophisticated sensing technologies, and the discoveries so far have been incredible. Airborne LiDAR (light detection and ranging), for example, is a powerful mapping technology that was first conceived in the ‘60s as a method for detecting submarines. It involves firing laser pulses over areas of interest in order to measure the distance between the ground and the aircraft. Some years after its introduction, researchers realized its potential as a tool for peeping through dense vegetation, and since then it’s been revolutionizing remote sensing in tropical environments.
While flying lasers around may sound expensive, considering it can uncover and map extensive regions without the need for time-consuming, labor-intensive ground surveys, it’s actually become a cost effective tool that’s proving invaluable to the field.
Just last year, a team of archeologists, headed by University of Sydney researchers, announced that they had used LiDAR to map 370 square kilometers around the world’s biggest religious complex—Cambodia’s Angkor Wat—in less than two weeks. Not only did this uncover a series of unexpected discoveries about the once lost city of Angkor, but it also revealed an even older city that archeologists had a sneaky suspicion lay hidden nearby.
This long-lost city, called Mahendraparvata, lay atop the Phnom Kulen mountain in the Siem Reap Province. This city was the original capital of the mighty Khemer Empire which was founded by a king called Jayavarman II. Mapping revealed almost 30 previously unknown temples alongside evidence of an extensive urban structure including canals, a grid of ceremonial boulevards, man-made ponds and roads. Some of these temples were so well hidden that the team believes they may never have been looted in the past.
LiDAR was also used back in 2009 to help construct a 3D map of an ancient Maya city in western Belize called Caracol. This metropolis was once again shielded by thick vegetation, and in less than one week the team collected more information about it than they had in a quarter of a century hacking through the tangled jungle. They found a plethora of agricultural terraces, roads and structures that were all previously unknown.
It seems that these impressive sensing technologies are bringing us into a golden age of archeology, and many of the discoveries made over the last couple of years have already challenged our conventional theories about ancient societies. Hopefully, now that this technology is beginning to be used more and more, archeologists will continue this current trend of discovery, bringing us closer to ancient civilizations than we could have ever imagined.