The closest comparison is Swiss cheese: holes in vast swaths of land where looters, armed with machine guns and bulldozers, take to ancient archaeological sites in search of loot. To the untrained eye, these holes, visible in satellite images, seem haphazard. But to experts, these deep pits, spanning hectares of land, are the work of sophisticated traffickers.
It's exactly the kind of looting that worries Mohamed Ibrahim Ali, Egypt's minister of state for antiquities. "The objects that are stolen from museums are easier to track because they are registered," Ibrahim said, referring to artefacts taken from Egypt's Malawi National Museum and Egyptian Museum in Cairo, many of which have been identified and returned. "The problem is the illicit digging everywhere. In Egypt, when you dig, you find something. So some gangs have started to become active very quickly because of the breakdown of the police force."
Looting isn't new. Ibrahim calls it a "centuries-old business" since objects were stolen from King Tut's tomb. But today, more than three years since the Egyptian revolution, looted antiquities have become a grave concern for a country dependent on historical tourism. And the confluence of economic, political and technological factors has made looting of ancient artefacts more problematic than ever. The ease of transport abroad, coupled with sky-high prices, make antiquities a sweet and easy target for organised thieves.
Ibrahim visited Washington in March to meet Obama administration officials to ask for emergency restrictions on the import of antiquities. Immigration and Customs Enforcement can currently seize artefacts from 16 countries if they appear to lack proper documentation, but Egypt isn't one of them. This month the state department will consider Egypt's proposal.
"The agreement would make us capable of controlling the situation," Ibrahim said. "Many objects are being sold here in the United States."
But stopping stolen objects from crossing US borders isn't the only option, experts say. Some worry that harsh restrictions will stop legal sales to museums. Others want to target looted objects at the source, and new technologies are putting the spotlight on the illicit trade long before items reach border control.
Sarah Parcak, an archaeologist at the University of Alabama at Birmingham, uses satellite imagery from DigitalGlobe, a satellite company, and Google Earth to identify what she calls "hot spots". Tracking regions where looting occurs, she says, may help law enforcement and officials identify looted artefacts before they turn up for sale.
"It was really hard before this technology to get a full sense of site damage from looting all over the world," Parcak said. "It was one thing to see the pits, but it was really hard to systematically count them. The satellite imagery allows us to track extent of damage at site – not only get a sense of numbers, but also track change to a site over time."
Parcak also noted that locating the movement in looted sites will help auction houses and traders scrutinise objects up for sale more closely. Since many objects are known to be from particular regions or eras of history, activity in an archaeological site could raise flags before sales even happen. Often, looters fake the provenance of an item, sometimes duping major houses or putting items on sites such as eBay, as was the case last year, when eBay removed 125 ancient Egyptian artefacts up for auction.
The Association of Art Museum Directors (AAMD), which sets standards for many US museums, has strict rules governing how museums deal with artefacts of suspicious provenance. In 2013, the organisation strengthened its guidelines.
"In the last decade, attitudes have changed fundamentally and so major museums like the Met, the Smithsonian and now AAMD are having a collective response," said Julian Raby, director of the Smithsonian's Freer Gallery of Art and Sackler Gallery. "I don't think anybody is unconcerned about the devastation of these sites and the distressing photographs from Iraq, now from Egypt. We now have to worry about the individual provenance of any single object."
The International Coalition to Protect Egyptian Antiquities, part of George Washington University's Capitol Archaeological Institute, is advocating on behalf of Egypt's call for temporary restrictions. But some in museums also caution against harsh restrictions, which could inadvertently cause the black market to grow. While established museums in the United States and Europe follow strict guidelines, new museums in developing countries and private collectors aren't necessarily operating under the same rules.
"The AAMD, anecdotally, is saying that the number of antiquities acquired by American museums has plummeted," Raby said. "Whether that creates a problem in terms of stewardship in the long term may well become an issue."