Drones bring new dimension to archaeology

Aerial surveys transform Oriental Institute studies of ancient dwellings, help track looting

Above the desolate landscape of the Black Desert in eastern Jordan, just north of the border with Saudi Arabia, a small drone used by an Oriental Institute team captures images of the landscape below.

At first glance, the mounds of basalt blocks dotting the land seem to be part of the natural terrain. A closer study, aided by aerial images, reveals the mounds to be hundreds of collapsed structures—a Neolithic community part of a trading system that extended as far as modern Turkey. Where only desert and ruins remain, a populated land flush with vegetation and fauna may have existed, as indicated by rock carvings of ibexes and other animals no longer native to the region.

The drone is one of many deployed by the archaeological team, which uses the remotely piloted aircrafts to fly close to the terrain and record features. The data are used in photogrammetry—integrating information from a series of photos—to produce a detailed, three-dimensional map of a landscape occupied 8,000 years ago. The drones also collect data on the modern problem of antiquities looting, as other strategies have had little success.

Since its founding in 1919, the Oriental Institute has pioneered use of other equipment, including airplanes, balloons, and kites, to capture bird’s-eye views of archaeological sites. Unmanned aerial vehicles, both small fixed-wing airplanes and multi-rotor vehicles, can survey the area more quickly and less expensively than traditional survey methods, and at higher resolution.

“We are in the middle of a revolution in aerial survey for archaeology,” says Yorke Rowan, senior research associate at the Oriental Institute. “Drones and photogrammetry provide a cost-effective means of quickly recording 3D data at a variety of scales for an array of research.”

Rowan, Gary Rollefson, professor of anthropology emeritus at Whitman College, and Alexander Wasse of the University of East Anglia are overseeing two projects in eastern Jordan: Wisad Pools and Wadi al-Qattafi—little-studied areas that contain large concentrations of collapsed basalt buildings. Projects there provide fresh insights on the late prehistoric era—a time when people organized communities, learned to herd livestock while continuing to hunt wild animals, and began a process that led to full-scale civilization.

“By using the drones, the project introduced an extremely useful new tool to Jordanian archaeology that will help us all as archaeologists to learn more about other archaeological sites in Jordan,” says Maysoon al Nahar, dean of the faculty of archaeology and tourism at the University of Jordan.

An uncharted horizon

The drones are helping to reveal details of the Neolithic sites that archaeologists missed for years. In the isolated sites, a five-hour drive from Jordan’s capital of Amman, small groups of Bedouin still live in the region. The watering holes at the Wisad Pools site sometimes fill over the winter and attract sheep and goat herders.

But when the area was used in Neolithic times, the climate may have been much different, Rowan says. “We have found remains of an oak tree that today grows only in the highlands of northern Jordan. This area was probably much more lush 8,000 years ago.”

The aerial photographs the drones provide are vital to the research team on the ground, helping scholars better understand how the ancient community was organized.

“We have already identified striking features that we didn’t know existed,” Rowan says, “like long walls running across the desert; some are the kites (hunting traps), and others are more enigmatic. These walls can be very difficult to notice from the ground because the land is fairly uniform, and the basalt in the Black Desert all looks so similar on the ground.”

The unmanned aircraft also are useful in capturing features too small to pick up in satellite images, which includes details on more than 400 rock carvings, depicting humans, structures, and geometric designs. Information on individual petroglyphs—chiseled sketches of animals made on rocks near watering holes—help researchers understand the species hunted in the past.

“Our goal is to use the drone in order to map these petroglyphs and, we hope, allow insights into the spatial distribution of rock art types,” says Rowan.

Mapping out the area also gives researchers a guide for future excavation, Rowan says.

The archaeologists have found a piece of obsidian, which came from Anatolia, modern-day Turkey, and fragments of pottery that are similar to a style produced in the Jordan valley, which help to date the site. Stone scrapers also were found, which may have been used to process hides into coverings over the basalt stone huts. The huts were possibly shelters for shepherds, Rowan says.

Following a modern problem

In Jordan, and throughout the Middle East, looters have frequently taken advantage of burial sites to find valuable artifacts that have a market in the West.

The drones have been useful in documenting the looting in a cemetery at Fifa, which dates from about 3600 to 3200 B.C., the Early Bronze Age. Looting began in the late 1980s, and the Jordanian government has found it difficult to curtail.

Hill co-directs the Landscapes of the Dead project with Morag Kersel, as part of the Follow the Pots Project, which records changes in the landscape using drones. The project plans to record changes from 2013 to 2018 to determine new looting episodes and evaluate the work of the government to reduce the destruction.

“The level of detail achieved by drone photography allows us to recognize every hole in the ground and quickly detect places where the ground has changed due to human or natural causes,” says Kersel, assistant professor of anthropology at DePaul University and a Neubauer Collegium Fellow.

Hill and Kersel report that drones can survey the entire area in a matter of days, at a resolution of 1 to 2 centimeters per pixel, allowing them to track minute changes across a cemetery spanning an estimated area of 64,000 square meters.

“We can document the fact that the site, which has been heavily looted in the past, still has a lot that’s available there,” says Hill. “There’s still archaeology of interest.”