When ISIS bulldozed the 3,000 year-old city of Nimrud, countless artifacts were lost. There are clandestine groups working to halt the destruction of Iraqi heritage through education and smuggling, while nearby countries are guarding what they can. But now many fear that all that remains of Nimrud’s impressive winged bull statues, intricate relief carvings and ancient walls are photos. Still, even those photos can be valuable. Archaeologists are using those images to create 3D reconstructions that can be studied digitally, reports Jonathan Webb for BBC News.

Photogrammetry is the technique used to build models out of many 2D images. When the video of ISIS militants smashing statues in Mosul Museum came out in February, two PhD students, Chance Coughenour and Matthew Vincent realized they could use that technique to reconstruct those statues digitally. They rely on crowd-sourced photographs from people who visited the artifacts before the conflict that destroyed them. Webb writes:

So they set up Project Mosul. People who have visited now-destroyed sites - beginning with the Mosul Museum - can submit their photographs. Then volunteers log on to help sort the images, and those with the know-how get stuck into the job of rebuilding the artifacts. The project has received more than 700 photos so far, including 543 showing artifacts from Mosul. A gallery on the homepage displays 15 3D reconstructions, completed by nine volunteers.

Statutes like that of a lion from Mosul Museum that have been photographed the most make the best reconstructions. The photogrammetry image is not as sophisticated as those created using things like laser scanning and calibrated cameras that can scan the intact object, but it is some way to preserve the statue’s memory and importance.

Webb writes:

Looking beyond Project Mosul, Mr Vincent is anxious that other digital preservation efforts should be undertaken more deliberately and proactively. Once a digital record has been created, it would even be possible to physically re-create precious items using 3D printing, he suggested. This could prove useful in building replicas not only of destroyed or lost artefacts, but also things that are too fragile to be put on public display - as was the case for the remarkable Chauvet cave paintings, now rebuilt above ground in France.

Even artifacts destroyed by natural disasters, such as the Dharahara tower toppled by the first earthquake in Nepal, could be preserved in this way.