(Mark Graham and Stefano De Sabbata/Information Geographies at the Oxford Internet Institute)

Talk about a series of tubes. This graphic, produced by Oxford Internet Institute  (OII) director of research and senior research fellow Mark Graham and researcher  Stefano De Sabbata, illustrates the submarine fiberoptic cables that keep data flowing across the world in the style of a London subway map.

The abstracted map features data sources from cablemap.info showing where the undersea cables that link the global Internet connect -- although with many short links excluded for the sake of simplicity. The "stations" represent all nodes located in the same country. The map also marks countries listed as "Enemies of the Internet" in Reporters Without Borders' 2014 report with icons denoting if countries engage in "censorship," "surveillance" or "imprisonment."

According to the researchers, the United States is the most connected country in the world in terms of undersea cables, with connections on both coasts to most continents. The second and third most centrally connected countries are on the other side of the Atlantic: the United Kingdom and Senegal. The latter is where most of the southern transatlantic cables land.

"The importance of being central in the submarine fibre-optic cable network is twofold," the researchers write. "On the one hand, Internet users in central countries tend to have faster and cheaper connections to the Internet — there are no countries with low-cost Internet access that aren’t also relatively well-connected."

But they also highlight that some countries central to the submarine cable network have a history of spying on Internet traffic. (Those include the United States and Britain, whose intelligence activities have been described in documents leaked by former National Security Agency contractor Edward Snowden.)

The map is part of an OII project called Information Geographies, which is aimed at producing "a comprehensive atlas of contemporary information and Internet geographies."

"Traditionally, information and knowledge about the world have been geographically constrained," Graham wrote in a column for the Guardian in 2012. "In the internet era, however, the movement of information is no longer constrained by distance." But still, he wrote, the digital geographies emerging show "massive inequalities" in the digital world that mirror those in the physical world.