An anonymous reader quotes Popular Mechanics:
Microsoft, Facebook and global telecommunication infrastructure company Telxius have completed the Marea subsea cable, the world's most technologically advanced undersea cable. The Marea crosses the Atlantic Ocean over 17,000 feet below the ocean's surface, connecting Virginia Beach with Bilbao, Spain. Over 4,000 miles (6,600 kilometers) long and weighing nearly 10.25 million pounds (4.65 million kilograms), the Marea can transmit up to 160 terabits of data per second, which Microsoft notes is "more than 16 million times faster than the average home internet connection, making it capable of streaming 71 million high-definition videos simultaneously."
The undersea cable -- about 1.5 times the diameter of a garden hose -- contains eight pairs of fiber optic cables encircled by copper, a protective layer of hard plastic, and then waterproof coating. Its 4,000-mile route had to avoid everything from earthquake zones to active volcanoes.
Cables under the Atlantic Ocean carry 55% more data than cables under the Pacific, Microsoft writes, adding that "the project highlights the increasing role of private companies in building the infrastructure of the future