If you are anything like me three weeks ago, you don’t know how the internet works. I thought it was just a big internet cloud in the sky and we talked to each other over radio waves or something. But recently, after taking my technological knowledge into my own hands, I was enlightened about the real workings of the internet! So now, I will enlighten you too.
Before the internet existed as we know it today, people could still make long-distance calls and transmit messages to different continents without using satellites. How did they do it? The answer lies in hundreds of undersea cables stretching 1.4 million kilometers across the planet.
In 1858, the first transatlantic telephone cable was laid on the ocean floor, connecting Europe and the United States. This was the first in a series of many cables laid in the 19th century connecting the east coast of the United States and western Europe. Initially, the cables transmitted Morse code and transported telegraph information. The first trans-Atlantic telegraph was 98 words and took 16 hours to send. In the 1950s, coaxial cables were introduced that could carry long-distance telephone calls over the ocean. Then, in the 1980s, the fiber-optic technology was installed that we use to transmit the internet all over the world today.
Fiber optic technology uses light signals to transmit information. Each fiber within a cable is made of glass and has the same diameter as a strand of human hair. The cables link all continents except Antarctica, making it possible for people all over the world to access the same content on the internet, call each other, and send text messages. According to the National Oceanic and Atmospheric Administration, about 95 percent of all international data and voice calls are carried by undersea cables.
Special cable layer ships unspool wound-up cables as the boats traverse the ocean. Roughly the same technology is used today to do this as was used in 1858 to lay the first undersea cable. Close to the shore and in shallow waters, the cables are buried underneath the ground so that humans do not disturb them. However, in the deep ocean, cables rest directly on the ocean floor. This leaves them exposed to human, animal, and geological disturbance. In 2021, about 55 percent of all damages to undersea cables were from humans, mainly from fishing and anchors. As climate change and overfishing push people to fish in deeper waters, cables are getting damaged more frequently.
These cables on the ocean floor do not exist in a vacuum: They share the space with organisms like fish, sharks, and whales. Over the nearly 200 years that humans have been using submarine cables, there have been many recorded incidents of animals interacting with the cables. Recorded whale interactions tend to involve whales getting tangled in the cables, which trap and kill them. Sharks have bitten the cables, which we know about because we have observed shark teeth embedded in the cable sheathings and shark teeth prints.
However, interactions with whales and sharks have been declining in recent years due to a few factors. First, cables have begun to be buried just underneath the ocean floor at depths of up to 2,000 meters, as this is the diving range of most whales and fish. More accurate mapping of the ocean floor has allowed the avoidance of rough areas of the seafloor where the cables are more likely to become tangled. Also, the addition of metal tape to the protective sheathing on the cables has helped to reduce shark bites, and there have been no recorded shark bites since 2006. Animal interactions do not pose a large threat to the preservation of undersea cables.
Although most people never see them, undersea cables are the foundation of our global economy and our global lives. They are how we can trade stocks internationally, stream content in multiple continents at the same time, and communicate with people living halfway across the world. So the next time you speak to a friend or family member overseas, or read a webpage that was posted in another continent, remember that that data traveled underneath oceans to reach you. Pretty amazing, right?
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