99% Of Our Internet Comes From Underwater Cables In The Ocean.
As of 2016 there are 299 cables that are active, under construction, or planned to be completed by the end of the year at the bottom of the ocean. Ninety-nine percent of international data is transmitted by wires at the bottom of the ocean called submarine communications cables. In total, they are hundreds of thousands of miles long and can be as deep as the height of Mt. Everest.
This concept of underwater cables is nothing new as the first installation transatlantic telegraph cable was done in 1854. The cable connected Newfoundland and Ireland. Four years later the first transmission was sent.
Why do we have these underwater cables?
- Underwater cables are much faster and reliable.
- They rarely fail.
- Submarine cable avoid data spying.
This brilliant vintage map comparing the map of trade routes in 1912 and map of submarine cables today is an example of how things have evolved.
Trade map of 1912
Today’s submarine cables
Do you know?
- The underwater cables are lightweight polyethylene cable for deep oceans is only 17 millimeters (.7 inch) thick.
- The optical fibers at the heart of the cable are made of highly purified glass that’s as thin as a human hair. Internal reflection is used to guide light along the path of the fiber.
- Many strands of these optical fibres are bundled within a large shell.
- The shell includes –
- Mylar tape
- Stranded metal (steel) wires
- Aluminum water barrier
- Copper or aluminum tube
- Petroleum jelly (this helps protect the cables from the water)
- Optical fibers
- The optical fiber is first embedded in a jelly compound to keep water out in case the cable is damaged.
- It is then encased in a steel tube to protect it from the water pressure as it will have to withstand 80 kms of water similar to something like placing a huge elephant on your thumb.
- Then it’s wrapped in steel wire for overall strength, followed by a copper tube to hold the wires together and transmit electricity to the repeater units along the cable that amplify the data signals.
- The final wrap is usually a polyethylene sheath to make it water resistant. Nowadays companies also use shark resistant shield to protect the cables from being eaten by sharks. As sharks are generally attracted to electromagnetic waves.
- Submarine cable is usually armored along the shores and continental shelves.
What can these cables do?
These cables carry videos, GIFs, information and articles like the one you’re reading right now. They can carry 100 wavelengths at 100 gigabits per second, it will have a peak capacity of 60 terabits per second (Tbps). That’s about 10 million times faster than a standard cable modem.