Here’s a fascinating look at undersea cables, also known as submarine communications cables. The first submarine communications cables, laid in the 1850s, carried telegraphy traffic. Subsequent generations of cables carried telephone traffic, then data communications traffic. Modern cables use optical fiber technology to carry digital data, which includes telephone, Internet and private data traffic. Continue reading for a video and more information.

As of 2012, operators had “successfully demonstrated long-term, error-free transmission at 100 Gbps across Atlantic Ocean” routes of up to 6000 km, meaning a typical cable can move tens of terabits per second overseas. Speeds improved rapidly in the last few years, with 40 Gbit/s having been offered on that route only three years earlier in August 2009.