Palmer-Felgate is a Verizon project manager who engineers and directs submarine-cable repairs all over the world, on about 80 cables leased or owned by Verizon. In the midst of the damage and devastation, the submarine cables lying along the ocean floor, which carried voice and Internet communications into and out of Japan, had also been severed.
After Fukushima, Palmer-Felgate helped direct the cable companies and engineers to pinpoint the location of the breaks by sending a pulse from a landing station on the coast and measuring the distance to the fault. His team piloted undersea remotely operated underwater vehicles (ROVs) to find the broken links; the operators then located, lifted, and rejoined the cables. Then they sent ROVs to blast jets of water to make a new trench to bury the cable. It took several weeks to restore the country's full connectivity, he says.
"The Japan earthquake caused a whole series of underwater landslides," he says. "At least seven of our cables were buried over by several kilometers of sediment."
Today there are over 200 submarine cables buried in the ocean worldwide, creating the backbone of the 21st-century world economy. In 2013 wireless carriers and dedicated cable installation companies will lay another 12 lines to connect even more countries. (For example, the small island country of Tonga is getting one this year.) The longest cables, stretching thousands of miles under the Atlantic and Pacific oceans, run at fantastic speeds: The total bandwidth stretching under the Atlantic runs at an amazing 19 terabits per second.
The burning question: What happens when they break, and what can we do about it?
Building Cables
When you send an email, a small collection of bits containing your message travels from a local server to a high-speed fiber-optic cable. These fibers, strands of glass that carry a waveform of light, move data at speeds up to 100 Gbps. One undersea cable might have hundreds of wavelengths per strand and several fibers. A submarine cable is about 0.75 to 2.5 inches in diameter, or about the thickness of three ordinary garden hoses. The longest cable, called the Southern Cross, runs under the Pacific, stretching 18,500 miles.
Most cables take several weeks to install. Surveyors must work with local fisherman, carriers, survey teams, and a number of private companies to determine the best route along the ocean floor, avoiding deep caverns and potential hazards. It takes a day to lay 80 to 90 miles of cable. In shallower waters near the shore, where there's more to go wrong, operators lay just 8 to 9 miles of cable a day.
The world's undersea cables. Via Telegeography.
Palmer-Felgate says the first step is to dig a trench near the shore, usually about 3 to 9 feet deep, using a huge plow dragged behind a 100-to-200-foot cable ship. The ship feeds the cable into the trench just behind the plow; sediment falls over the cable to protect it. ROVs then fire jets of water to blow more sediment to fill over the newly installed cable. (In much deeper waters, where there is less risk to the cable, engineers lay it directly on the seabed.)
Andrew Blum, the author of the book Tubes: A Journey to the Center of the Internet, says that with each new installation, the world becomes more connected. African countries such as Nigeria and Cameroon are the center of a lot of current construction. With data speeds approaching 100 Gbps per fiber-optic strand (10,000 times faster than a 10-Mbps line to your home or workplace), it's no wonder there is an ongoing effort to link the world by submarine cable.
Breaks Happen
Redundancy is another reason the seafloor cable-building craze continues. On Valentine's Day, according to Internet monitoring company Renesys, a fire in Alexandria, Egypt, severed six of the submarine cables on the coast. There was a widespread Internet outage in several East African countries, including Kenya.
"That was a reminder, when the Kenyan cable went down, that you really need two or three?that one [cable] is not enough to build an economy," Blum says. "It made everyone nervous because the cables were too close together?there is a greater risk."
Breaks occur most often when a ship drops anchor near a submarine cable, snags the cable, and ruptures it. (Ships use maps that show the cable lines, but sometimes ignore them or forget.) Anchors cause about 70 percent of all breaks, Palmer-Felgate says. Another 10 percent come from fishermen who are unaware they're dragging up more than just tuna. Natural disasters can also cause major breakages, such as what happened in Japan.
What hasn't happened yet, according to the firm TeleGeography, is a terrorist attack?though given their status as crucial infrastructure, the cables would be tempting targets. Blum says the cables are designed for redundancy, especially in areas like L.A. and New York City, where there might be 10 lines running into multiple landing stations.
"Cutting submarine cables is as hard as cutting off all air traffic to New York," Blum says. "To cut off New York, you'd have to cut at least 10 cables. There is still a possibility to bring traffic in around Asia and Europe. You could isolate a place like Australia or a Pacific island. If you succeed in cutting five cables, you'd be perceived as cutting off the global economy. Unless you were fully successful, you'd have negligible impact." Palmer-Felgate says companies like Verizon install multiple submarine cables and automatically reroute web traffic when a break occurs.
Although there have not been attacks, these cables are at the center of national security disputes. For example, the proposed $300 million trans-Atlantic Hibernian Express project is delayed because of rising cybersecurity tensions between China and the U.S.
Diversify, Diversify, Diversify
The real problem with undersea cables and infrastructure security is not that cables break and need to be repaired. Most of the experts said natural disasters will continue to break undersea cables and ships will drop anchor in the wrong places. Instead, Blum says, the real issue has to do with a lack of diversity on the Internet.
"There is no doubt [that] as more and more things connect to the Internet, everything becomes the Internet," Blum says. "The best way to embrace the health and safety of the Internet is to embrace the ?inter'?to embrace this network of networks. The more networks there are, the more robust it is. The greatest risk is any single network getting too large. It is the Googles and the Verizons and the Comcasts that are the greatest risk to the Internet," he says, because having so few companies in control means you lose checks and balances.
The Internet should not be viewed as a single holistic thing. It is a place with great diversity, with many different ideas and people groups. The diversity is what ensures safety and redundancy, he says. The more a network spreads out, like a contagion that crosses geographic boundaries, the more powerful it becomes. That's ultimately the goal: more lines and more companies involved.
As for Palmer-Felgate, there is no question his team will keep repairing undersea cables. In the U.S. there might only be one fault per year, but in other countries, say, off the eastern coast of China in winter, there may be one cable break per week. In a world wrapped by 1000-mile fiber strands, breaks are a way of life.
"Engineers are constantly working to improve the armoring of cables, improve the routing of cables to avoid fault-prone areas, and bury cables more," says Alan Mauldin, a researcher at TeleGeography. "I am not sure you can ever engineer something that is 100 percent reliable, but cables are very reliable if you consider the harsh environments in which they operate."
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