Archaeologists Are Using Google Maps to Protect Ancient Tombs From Raiders

Space-age satellites are watching over centuries-old artifacts.

Google Maps may be a useful tool for finding the nearest store open at 10 p.m., but a team of archaeologists have discovered a use-case that’s inarguably more profound: protecting humanity’s most precious cultural sites and warding off grave robbers. A new research paper published Monday shows how experts can use satellite images of remote areas to identify sites under threat and take action, not unlike the archeologist-aiding drones depicted in the above video.

This team focused on an area of northern Xinjiang in China. Nestled in the hills are burial mounds called “kurgans,” left by nomadic tribes over 2,500 years ago, filled with precious artifacts. The team used Google Maps and two other image sources, analyzed by hand with experts on the region’s “kurgans,” in combination with real-life analysis to check the data. While A.I.-powered tools exist for these checks, the team wanted to make sure the results matched with expert opinion.

The team was hopeful that, because of their remote location and the high levels of security in Xinjiang, the mounds would be relatively intact — but they were horribly mistaken, with a staggering 74.5 percent of mounds either looted or destroyed. While a vast amount of damage is already done, the research published in the journal Heritage could prevent further destruction.

An example of a ransacked mound.
An example of a ransacked mound.

“The main issue with remote sensing is so-called groundtruth — actually checking if what you see in the data is what you think you see,” Gino Caspari, author of the paper from the Institute of Archaeological Sciences at the University of Bern in Switzerland, tells Inverse. “At the moment this is not possible in northwestern China, since access for foreigners is so restricted. But through showing how it is done, the Chinese cultural heritage administration can absolutely implement protection measures and monitor the sites themselves.”

A map showing the research area.
A map showing the research area.

The tribes honored the dead by burying them with elaborate jewellery and finely-crafted weapons. They would dig a pit, then cover the contents with a mound of stones or earth. Over the centuries, many of the “kurgans” across the Eurasian steppe were ransacked, particularly in the 18th century when groups of up to 300 people would work through the summer and melt down the artifacts at the site, ready to sell the bronze and gold.

A sample of the sort of prehistoric treasures found in these tombs.
A sample of the sort of prehistoric treasures found in these tombs.

The team looked at the satellite images to see whether these mounds had been uncovered, shown by a depression in the soil. The team used Ikonos and Worldview-2 data provided by the DigitalGlobe Foundation alongside Google Maps, before comparing the three to an on-site analysis of 188 mounds.

While Google Maps and Worldview-2 matched the data to a very high degree, Ikonos identified notably few mounds. The paper speculates that this is because the latter photos date back to 2003, while Google Maps and Worldview-2 were captured in 2012 and 2011 respectively. If that’s the case, it could point to a sudden surge in looting, perhaps fueled by the opening of the nearby Kanasi Airport in 2007, which may have created a market for selling trinkets to tourists.

Looted tombs as seen in the images.
Looted tombs as seen in the images.

The research showed that satellite images can provide a good approximation of the scale of destruction for tomb sites. The techniques could encourage the use of better data, perhaps captured by drones.

“Higher resolution data would of course help, but it is a major cost factor,” Caspari says. “I specifically worked with open-source data because you have to monitor very large areas.”

The breakthrough could protect a key cultural site from further destruction. In a statement announcing his findings, Caspari said that “the last untouched archeological sites of the ancient steppe nomads are under threat.”

A burial mound on the Eurasian steppe under threat.
A burial mound on the Eurasian steppe under threat.

Read the abstract below:

Burial mounds (kurgans) of the Early Iron Age in the steppe zones of Central Asia have long been the target of severe looting activities. Protection of these monuments in remote areas is difficult since accurate mapping is rarely available. We map an area in northern Xinjiang using a combination of high-resolution optical data and on-ground survey to establish a quantitative and qualitative assessment of looting. We find that at least 74.5% of burial mounds are looted or otherwise destroyed. Due to the large number of visibly impacted burial mounds, it becomes clear that the bulk of cultural heritage of the Early Iron Age in this area is under threat. The looting, however, continues until present day. Rescue excavation of potentially untouched burials in the area is advisable.

Related video: Google Maps Introduces Accessible Transit Routes

Media via Trevor Wallace, Gino Caspari, DigitalGlobe, Michael Jendryke, Inverse