CNN have a beautiful gallery online: This is what the Internet actually looks like: The undersea cables wiring the Earth
The information age is powered by thin fiber-optic cables buried in the sea bed, spreading between continents to connect the most remote corners of the planet. These great arteries account for practically all of our international web traffic, and each one has been logged by Washington research firm Telegeography in its interactive Submarine Cable Map 2014. The company's research director Alan Mauldin told CNN about the world's underwater networks.
The full map is on the TeleGeography web site: Submarine Cable Map 2014.
I'd love to buy the full map for my wall at work, but it's a bit out of my price range. To be accurate, it's priced at about 10x what I'd be willing to pay.
Still, the online version of the map is simply beautiful.
Are the cables actually "buried in the sea bed"? For some reason I thought they were just resting on top of the sea floor.
Wow, has it really been 18 years since Neal Stephenson wrote Mother Earth Mother Board ? Time sure passes quickly...
Here's what Stephenson said, at the time:
The amplifiers need power - up to 10,000 volts DC, at 0.9 amperes. Since public 10,000-volt outlets are few and far between on the bottom of the ocean, this power must be delivered down the same cable that carries the fibers. The cable, therefore, consists of an inner core of four optical fibers, coated with plastic jackets of different colors so that the people at opposite ends can tell which is which, plus a thin copper wire that is used for test purposes. The total thickness of these elements taken together is comparable to a pencil lead; they are contained within a transparent plastic tube. Surrounding this tube is a sheath consisting of three steel segments designed so that they interlock and form a circular jacket. Around that is a layer of about 20 steel "strength wires" - each perhaps 2 mm in diameter - that wrap around the core in a steep helix. Around the strength wires goes a copper tube that serves as the conductor for the 10,000-volt power feed. Only one conductor is needed because the ocean serves as the ground wire. This tube also is watertight and so performs the additional function of protecting the cable's innards. It then is surrounded by polyethylene insulation to a total thickness of about an inch. To protect it from the rigors of shipment and laying, the entire cable is clothed in good old-fashioned tarred jute, although jute nowadays is made from plastic, not hemp.
Oh wait, no, there's more later (Stephenson wrote a LONG article...). Here it is:
At Tong Fuk, FLAG is encased in pipe out to a distance of some 300 meters from the beach manhole. When the divers have got all of that pipe bolted on, which will take a week or so, they will make their way down the line with a water jet that works by fluidizing the seabed beneath it, turning it into quicksand. The pipe sinks into the quicksand, which eventually compacts, leaving no trace of the buried pipe.
Beyond 300 meters, the cable must still be buried to protect it from anchors, tickler chains, and otter boards (more about this later).
Well, that wasn't it, exactly, as that's still talking about the part where the cable reaches land. How about this part:
These nozzles fluidize the seabed and thus make it possible for the giant blade to penetrate it. Along the trailing edge of the blade runs a channel for the cable so that as the blade works its way forward, the cable is gently laid into the bottom of the slit. The barge carries a set of extensions that can be bolted onto the top of the injector so it can operate in water as deep as 40 meters, burying the cable as deep as 9 meters beneath the seabed. This sufficed to lay the cable out for a distance of 10 kilometers from Tong Fuk. Later, another barge, the Chinann, will come to continue work out to 100 meters deep and will bury both legs of the FLAG cable for another 60 kilometers out to get them through a dangerous anchorage zone.
Still seems like we're talking about the part close to shore.
OK, no, here it is (I knew I remembered it):
The route between the landing station at Songkhla, Thailand, and the one at Lan Tao Island, Hong Kong, might have a certain length when measured on a map, say 2,500 kilometers. But if you attach a 2,500-kilometer cable to Songkhla and, wearing a diving suit, begin manually unrolling it across the seafloor, you will run out of cable before you reach the public beach at Tong Fuk. The reason is that the cable follows the bumpy topography of the seafloor, which ends up being a longer distance than it would be if the seafloor were mirror-flat.
Over long (intercontinental) distances, the difference averages out to about 1 percent, so you might need a 2,525-kilometer cable to go from Songkhla to Lan Tao. The extra 1 percent is slack, in the sense that if you grabbed the ends and pulled the cable infinitely tight (bar tight, as they say in the business), it would theoretically straighten out and you would have an extra 25 kilometers. This slack is ideally molded into the contour of the seafloor as tightly as a shadow, running straight and true along the surveyed course. As little slack as possible is employed, partly because cable costs a lot of money (for the FLAG cable, $16,000 to $28,000 per kilometer, depending on the amount of armoring) and partly because loose coils are just asking for trouble from trawlers and other hazards. In fact, there is so little slack (in the layperson's sense of the word) in a well-laid cable that it cannot be grappled and hauled to the surface without snapping it.
So at least when Stephenson wrote about this, twenty years ago, the cable was only buried in the seabed close to shore, to prevent it from being damaged by dragging anchors and other dangerous things that arise in the shallow ocean close to land.
Out deeper, they just laid it down on the sea floor.
So, has that changed? If you know, let me know.