Guest Post: Using GIS to Document Archaeological Looting

Today, I was invited to host a guest blog post from a University of North Dakota and Pyla-Koutsopetria Archaeological Project alumnus Brandon Olson who is now a Ph.D. student in archaeology at Boston University. His post is on looting, an issue that anyone who does Mediterranean archaeology has experienced and has become an issue at our site on Cyprus and on numerous sites in the Corinthia. Brandon’s post discusses the use of GIS and satellite imagery to track looting at a site of Carrhae, modern Harran, in Turkey.

Looting has been and continues to be a direct threat to our material past. Whatever its impetus (profiteering, subsistence digging, collecting, etc.), the nefarious act typically takes place under the cover of darkness, during periods of unrest, or in far-removed areas. As such, it is difficult for interested parties who seek to deter illicit digging to identify and document damage. Whether the goal is to develop a cultural management plan, to write in support of a Memorandum of Understanding (see for example), or simply to raise awareness and protect a particular archaeological site, there is a need to supplement narrative description accompanied by limited visual evidence with new methods that can make the point in a more dramatic, more complete, and more compelling manner. The continued development and accessibility of high resolution satellite imagery coupled with ArcGIS provides a powerful tool to document, measure, display, and analyze looting in a meaningful way.

Focusing their efforts on large tel sites in war-torn regions of the Middle East, scholars such as Elizabeth Stone and Carrie Hritz, among others, have used a GIS platform and high resolution imagery of varying dates to document looting over time. Their studies clearly demonstrate that in areas experiencing civil unrest, unprotected archaeological sites often fall victim to illicit digging. Here I demonstrate their technique by focusing on the ancient site of Harran in southeastern Turkey.

First occupied in the third millennium BCE, the site of Harran, ancient Carrhae, has a storied past. Of the archaeological material visible today, the classical and later periods are the most prevalent. During Rome’s First Triumphal period, the site served as a meeting ground for a Roman army led by Marcus Licinius Crassus, one of the three triumvirs, and the Parthians. At the Battle of Carrhae, the Parthians soundly defeated the Romans and Crassus lost his life. On a visit to the area in 217, Martialis, an imperial officer, assassinated the Roman emperor Caracalla. In the middle of the eighth century, a large mosque was constructed, the remains of which are still visible today. In visiting the site in the summer of 2010, I was, above all else, struck by the condition of the walled city. Three fenced off areas protect two excavation areas and the ruins of the mosque, but hundreds of looter holes littered with broken potsherds blanket the site (Picture 1).

Picture 1Picture 1

Using GeoEye imagery provided free of charge by Google Earth, I first saved a series of JPEGs at multiple scales and imported the files into ArcMAP. After rectifying the images, I began digitizing all visible looter holes within the northern half of the site. Unfortunately, GeoEye does not provide high-resolution coverage for the southern half. At half-meter resolution, the satellite imagery depicts looter holes as small as 1.5 meters in diameter. In all, I identified 1,003 distinct areas of illicit digging. Map 1 depicts the GeoEYE imagery before digitization, note the small circular holes indicative of illicit digging, while Map 2 includes the digitization. The maps help identify the scope, range, and scale of looting activities. The densest activity occurs just east of a small cluster of houses situated on the western edge of the site.

Map 1Map 1

Map 2Map 2

 

The utilization of ArcGIS and satellite imagery is a powerful tool to document looting. Examining spatial relationships, quantifying the damage, and providing meaningful visual representation are all strengths of such an approach. The damage depicted on the Harran maps, moreover, make a specific statement:

Illicit diggers actively threaten the archaeological heritage of Harran and southeastern Turkey.
For those who would like to use such methods for their own purposes, I provide links below to free and moderately priced high-resolution imagery.

http://edcsns17.cr.usgs.gov/NewEarthExplorer/
http://digitalglobe.com/products#imagery
http://www.google.com/earth/index.html
http://gaialab.asu.edu/Jordan/
http://cast.uark.edu/home/research/geomatics/photogrammetry/corona-satellite-imagery-based-digital-archaeological-atlas-of-the-near-east.html

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