Drone survey reveals large earthwork at ancestral Wichita site in Kansas

[Judi Lynn]

6. How Drones Help Archaeologists Peer Into the Earth

A late-night drone flight spotted a large, circular earthwork beneath a field in Kansas.
BY KAREN CHERNICK
OCTOBER 9, 2020



An aerial view of a portion of the site that a drone surveyed in Kansas. JESSE CASANA

FOR THE ARCHAEOLOGIST JESSE CASANA, midnight is the best time to find things underground. “It’s always in the middle of the night, sometime between late and very late,” he says. Casana, an anthropology professor at Dartmouth, has been testing a new thermal imaging drone for archaeological research. “It’s a very weird kind of archaeology because usually we go and spend weeks and weeks working in the sun. In this case we just go in the middle of the night—once.”

The advantage of late-night archaeology is that big, underground objects retain and emit heat at different rates than the soil surrounding them. Take thermal images of the ground at just the right moment, when everything is cooling down, and you’ll see clear subterranean variations that may be undetectable using other methods.

Casana has a grant from the National Endowment for the Humanities to test this thermal imaging drone in different environments around the world, and for different archaeological features. So far, he’s spent sleepless nights using the device in the Middle East, Hawai‘i, and Mexico. Archaeologists keep asking him to fly out to particular patches of land that they’re curious about.

One such request came from Donald Blakeslee, an archaeology professor at Wichita State University. Blakeslee and his team had already experimented with a drone, but its regular camera didn’t register enough detail. They also used magnetometry, ground-penetrating radar, and electromagnetic conductivity devices. These methods were all noninvasive and faster than digging, but still considerably slower than Casana’s drone, which could survey a 45-acre cattle ranch in just two nights.

More:
https://www.atlasobscura.com/articles/drone-archaeology-finds-underground-earthworks