New archaeological non-invasive scanning technology

TECHNOLOGY WATCH:

An Israeli technology that's groundbreaking - literally
4 May 2011
A new geophysical tool for zeroing in on ancient artifacts buried deep underground could be a boon for archeologists and excavators.

By Jenny Hazan (Israel Ministry of Foreign Affairs)

Archeologists around the world rely on a repertoire of only partially effective methods - historical texts, surface indicators and technology - to decide where to break ground to uncover sites of archeological significance. But the decision often comes down to educated guesswork, because it isn't possible to get a really clear look at what is going on underground.

Now it is, thanks to Prof. Lev Eppelbaum of Tel Aviv University's Department of Geophysics and Planetary Sciences. Eppelbaum has created a new non-disruptive, ecologically sound geophysical methodology, an "algorithmic toolkit," capable of cutting through the "background noise" of irrelevant underground features. It can detect archeological structures and artifacts up to 150 meters deep, producing an accurate 3D or even 4D image.

"It's the most conclusive evidence ever produced about what's below the ground's surface," says Eppelbaum, who immigrated to Israel from Azerbaijan in 1990. "Until now it was very difficult to reveal relevant archeological components, given the strong background noise of irrelevant components, and now it's possible."

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Eppelbaum's method, dubbed the "Multi-PAM" (physical archeological models) System, uses a combination of up to seven different geophysical components to get an estimation of the underground landscape: magnetism; gravity; self-potential; VLF (very low frequency electromagnetic radio transmissions, the type the military uses to communicate with nuclear submarines deep below the water's surface); resistivity; induced polarization (based on differences in electromagnetic properties); and piezoelectricity, which detects minerals and some archaeological objects made from fired clay.

In most cases, not all seven methods are applied; mostly because of the expense. "Usually we can get an accurate image using two or three methods per site," the former chess champion says. Eppelbaum explains that the survey technology can be strapped to a remote-operated unmanned aircraft, the kind most often used by the military, and sent to scan the desired tract of land. The data it returns is then converted into an advanced mathematical algorithm that can be translated into a model image.

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