LiDAR scanning reveals sprawling ancient metropolis in Mexico

Using sophisticated laser surveying technology, archaeologists have discovered a “lost city” in western Mexico that may have been home to as many buildings as Manhattan.

One of Angamuco’s ‘neighbourhoods’, revealed using light detection
and ranging scanning [Credit: C Fisher]

A team of researchers, led by Colorado State University archaeologist Chris Fisher, was able to use LiDAR technology to determine that the ancient city of Angamuco had around 40,000 buildings spread over an area of 10 square miles. That’s roughly about the same number of buildings as Manhattan, but on a much smaller plot of land as the New York City borough is 22 square miles.

Fisher told Fox News that without the use of the LiDAR technology figuring out the number of buildings at the Angamuco site might have taken his entire career. But with just two flights using LiDAR, one in conjunction with the National Center for Airborne Laser Mapping, his team was able to determine the size of the city and also find previously uncovered structures.

“I almost started crying,” Fisher said of seeing the LiDAR images of the city for the first time. “It was incredible to see these buildings in such clear definition.”

LiDAR uses a laser to measure distances to the Earth’s surface and can prove extremely valuable to study what is hidden in heavily forested areas. LiDAR is also used extensively in other applications, including autonomous cars where it allows vehicles to have a continuous 360 degrees view.

The city of Angamuco, which occupies a lava field on the eastern edge
of the Lake Pátzcuaro basin [Credit: C Fisher]

Fisher is quick to point out that Angamuco is not technically a “lost city” as it was first discovered in 2007 and his team has been conducting research there since 2009.

“We don’t call it a lost city,” he said. “We call it an undocumented city.”

Despite this, the archaeologist is not downplaying the impact the discovery could have his field of research and science overall.

“This is another demonstration that this is the 21st Century and we still know so little about our world and there is still so much to be discovered,” Fisher said. “This city is in a highly trafficked area of Mexico and nobody knew that it was right there the whole time.”

Angamuco was built around 900 AD by the Purépecha, a civilization that was a rival of the Aztec empire in central Mexico, and reached its peak population of around 100,000 residents somewhere between 1000 and 1350 AD.

Examples of sunken plazas, patios, and related features in Angamuco
[Credit: C Fisher]

"There are roughly a similar number of buildings but the size of the ancient buildings is obviously much smaller so the population density or number of people involved is not comparable," Fisher added.

At its height it was the largest city in western Mexico and much larger than the Purépecha imperial capital of Tzintzuntzan, although most likely not as densely populated.

“[Angamuco] was the real core of the empire,” Fisher said.

The city was built over a lava flow and has been hidden for centuries due to the dense forest and rugged terrain that surrounds it.

Colorado State University archeologist Chris Fisher has used the laser mapping technique
 in Mexico and Honduras [Credit: Colorado State University]

Researchers have found a number of interesting features that make Angamuco different from other pre-Colombian cities in Mexico. The majority of the city’s temples and open plazas sit in eight places around the edges of Angamuco, rather than the center, which is more common.

The city also had numerous gardens and the Purépecha were known for their ability to divert water flow to grow crops and cultivate green spaces.

“We can learn a lot from the Purépecha in regards to modern city planning,” Fisher noted. “They had green spaces, they did things with water that we’re still trying to implement. These guys had it all figured out.”

Radio carbon dating of artifacts discovered at the site suggests that the city went through two separate periods of expansion before its eventual collapse preceding the European arrival in the Americas in the 15th Century.

Author: Andrew O'Reilly | Source: Fox News [February 20, 2018]