Laser scanning reveals ‘lost’ ancient Mexican city ‘had as many buildings as Manhattan’
Archaeology might evoke thoughts of intrepid explorers and painstaking digging, but in fact researchers say it is a high-tech laser mapping technique that is rewriting the textbooks at an unprecedented rate.
The approach, known as light detection and ranging scanning (lidar) involves directing a rapid succession of laser pulses at the ground from an aircraft.
The time and wavelength of the pulses reflected by the surface are combined with GPS and other data to produce a precise, three-dimensional map of the landscape. Crucially, the technique probes beneath foliage – useful for areas where vegetation is dense.
Researchers have used the technique to reveal the full extent of an ancient city in western Mexico, about a half an hour’s drive from Morelia, built by rivals to the Aztecs.
“To think that this massive city existed in the heartland of Mexico for all this time and nobody knew it was there is kind of amazing,” said Chris Fisher, an archaeologist at Colorado State University who is presenting the latest findings from the study at the conference of the American Association for the Advancement of Science in Austin, Texas, this week.
Following misrepresentations by a white nationalist leader and coordinated efforts by internet trolls, numerous researchers and media outlets spread a seemingly false claim that the man charged with killing more than a dozen people at a Florida high school belonged to an extremist group.
Law enforcement agencies say they have no evidence so far to support this claim, and the rumor appears to have been perpetrated by white nationalist trolls themselves.
Joan Donovan, a researcher who tracks online misinformation campaigns for Data & Society, a think tank in New York City, called this an instance of “source hacking,” a tactic by which fringe groups coordinate to feed false information to authoritative sources such as ADL researchers. These experts, in turn, disseminate the information to reporters, and it reaches thousands of readers before it can be debunked.
“It’s a very effective way of getting duped,” Donovan said.