Most people know that our world’s oceans are filled with underwater internet cables which transmit data from one side of the world to the next at the speed of light.
But most people don’t know anything about how those cables work. What do the cables do? What are they made of? And what happens if a cable breaks?
Well, we know a lot more about underwater internet cables thanks to recent statements by Google manager Dan Belcher.
Belcher recently spoke at the opening keynote of Google’s Cloud Roadshow which took place in Boston last week. In that statement, Belcher discussed how underwater sea cables work. Belcher also explained that Google was investing heavily in underwater infrastructure – including Kevlar-coated cables which are specially designed to protect cables from shark teeth.

Sharks are attracted to the electric field generated by cables

In days gone by, we used copper cables to transmit information from one end of the world to the other.
Those copper cables generated an electric field whenever a current passed through. This current inevitably attracted the occasional curious shark.

However, today, we use fiber-optic cables to connect our world. Fiberoptic cables generate a stronger electric field than copper cables.
Sharks are attracted to this stronger electric field. The field is thought to resemble the field generated by some of the shark’s most common prey.
Information passing through these cables triggers the shark’s hunting instinct, which causes many sharks to attack the cables and, in some cases, cause serious damage.

A problem since the 1980s

Sharks have been gnawing on undersea cables since the 1980s. While there have been a few documented shark attacks on cables over the years, they have likely been thousands more undocumented cases: it’s not like cables are being constantly monitored for shark attacks.
One of the coolest things to come from this story is this video of a shark actually attacking an undersea cable:

All of these undersea cable attacks have caused Google to invest in Kevlar-proofed underwater infrastructure.
Communications companies have been searching for years for a reliable way to protect their cables against shark attacks. That’s why Google has turned their engineers towards solving the problem.

The solution is in double layered cables

Apparently, Google believes double-layered steel cables coated with Kevlar are the best way to protect our underwater internet supply lines.
These double-layered internet cables reduce the electric current propagated by undersea cables while also providing substantial protection against shark attacks.

Of course, it’s not just sharks causing problems for underwater cables. There are anchors, propellers, and other boat traffic to consider.

What happens when a cable is cut?

Internet supply lines are rarely cut. But when they are cut, it causes some serious problems.
The most famous incident was the 2008 submarine cable disruption which brought down internet connections in the Mediterranean Sea, Middle East, and India.
For some countries, internet connections disappeared entirely. In most areas, however, internet was just extremely slow until the cables were repaired (the internet connection was routed to the area using other undersea cables).
When the internet goes down, it’s not just your YouTube videos and Facebook browsing that gets affected. It can send entire economies into a tailspin.
That’s why shark-proof submarine internet cables are worth so much money: and that’s why Google is developing a solution.