live, global locations of cableships

The locations of the world's submarine fiber optic repair ships, 25 October 2010.  Source

The global flows of digital information require submarine fiber optic linkages between continents.  Since these cables are laid atop or just below the surface of the ocean floor, they are susceptible to being damaged by a number of sources, but primarily by fishing vessels dragging a net or anchor.  Consequently, a fleet of cable repair ships sit ready in most major ports worldwide to mend a break.  The 'x' is a sitting ship, and the triangles indicate moving ones.  One could deduce most important cable routes as well as the places with regular problems by the clustering of 'x's and triangles.  The English Channel, the Mediterranean, the Gulf of Oman, the Gulf of Aden, and the East China Sea.  If a cable becomes damaged in a location without a cableship nearby, as happened to east Africa's Seacom cable in late July, the ICT linkages could be down for a while.  Looking at this map, it seems that if a cable goes out in much of the Southern Hemisphere, unless a redundant link is in place, the affected regions could be without telecommunication linkages for a length of time, until a cableship is able to motor south to fix the outage.

submarine fiber optic cables attacked by sharks

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In the 1980s AT&T was prototyping submarine telecom cable by laying they between the Canary Islands, where the cables were attacked by crocodile sharks

Buried in the final section of a Rand Corporation study into the feasibility of a new platform for deep-sea submarines, is a chapter about the history of submarine cable infrastructure.  In an otherwise dry paragraph about the dangers from dragged anchors and the like that submarine cables face on the ocean floor, was this sentence:

"Between 1985 and 1987, AT&T found that its first deep-sea submarine fiber optic cable (laid between the Canary Islands, Grand Canaria and Tenerife) suffered periodic outages because of frequent attacks of the Pseudocarcharias kamoharai, or crocodile shark, on the cables."

The crocodile shark.  Source

A footnote goes on to explain that "The electric fields of which, it was thought, duplicated that of the shark’s prey under attack."*

I find this fascinating, and slightly amusing, that the globally networked fiber-optic communication system could be damaged enough to cut out by a shark attacking the cable.  Information and communication technologies exist as physical abstractions, of data flows between New York and London's financial centers that dictate the rise or fall of the day's stock trades, and out of nowhere the infrastructure could fail because of a hungry and/or angry shark, at the bottom of the Atlantic Ocean.

*source: Martin, Rick, “Life History and Behavior of Lamnoid Sharks,” from ReefQuest Expeditions, 2001.