Have you ever wondered how Internet use spread to every country in the world, and how data is able to travel between continents? Contrary to what many believe, the majority of data exchange doesn’t happen via satellites or some powerful antennas, but through undersea cables. Yes, humans have actually connected all continents with powerful submarine cables, which have been used for communication purposes for over a century.

The first cable was laid on the sea bed in the 1850s when the only way to communicate instantly between continents was via telegraph. A few decades later, beginning in the 1940s, the cables were used for telephone connections, and eventually in the late 20th century, new generation of cables began transferring digital Internet data across the sea. Specially equipped ships, like the one in the picture are commonly used to lower cables into the water.

Governments and big corporations eventually invested a lot of money and connected all continents by laying thousands of miles of cables in the World’s seas. If you’d like to know where all these cables are, you can check out this interactive submarine cable map made available by the TeleGeography company.

According to Wikipedia,”as of 2006, overseas satellite links accounted for only 1 percent of international traffic, while the remainder was carried by undersea cable”. The reason for that is simple – it is because the submarine cables are very reliable.  That’s why they have been used for decades, and it’s unlikely they’ll be replaced any time soon.

If you would like to read up more about the history of the submarine cables, please go to Wikipedia’s Submarine communications cable page.

Source: Wikipedia and Telegeography.

Image source: http://en.wikipedia.org/wiki/File:CABLE_INNOVATOR.jpg