Editing Submarine communications cable (section)

{{Short description|Transoceanic communication line placed on the seabed}}
{{use mdy dates|cs1-dates=ly|date=October 2022}}

[[File:Submarine cable cross-section 3D plain.svg|right|thumb|upright=1.35|A [[cross section (geometry)|cross section]] of the shore-end of a modern submarine communications cable.<br />
1 {{color box|#C0D483}} – [[Polyethylene]]<br />
2 {{color box|#A493DC}} – [[BoPET|Mylar]] tape<br />
3 {{color box|#89B0D1}} – Stranded [[wire rope|steel wires]]<br />
4 {{color box|#C9C9C9}} – Aluminium water barrier<br />
5 {{color box|#A6A6A6}} – [[Polycarbonate]]<br />
6 {{color box|#E5AA5A}} – Copper or aluminium tube<br />
7 {{color box|#E5D56D}} – [[Petroleum jelly]]<br />
8 {{color box|#EEEEFF}} – [[Optical fiber]]s]]
[[File:France Telecom Marine Rene Descartes p1150247.jpg|thumb|Submarine cables are laid using special [[cable layer]] ships, such as the modern ''{{ill|René Descartes (ship)|fr|René Descartes (câblier)|lt=René Descartes}}'', operated by [[Orange Marine]].]]

A '''submarine communications cable''' is a cable laid on the [[seabed]] between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables were laid beginning in the 1850s and carried [[telegraphy]] traffic, establishing the first instant telecommunications links between continents, such as the first [[transatlantic telegraph cable]] which became operational on 16 August 1858.

Submarine cables first connected all the world's [[continent]]s (except [[Antarctica]]) when [[Java]] was connected to [[Darwin, Northern Territory]], Australia, in 1871 in anticipation of the completion of the [[Australian Overland Telegraph Line]] in 1872 connecting to [[Adelaide, South Australia]] and thence to the rest of Australia.<ref>Anton A. Huurdeman, ''The Worldwide History of Telecommunications'', pp. 136–140, John Wiley & Sons, 2003 {{ISBN|0471205052}}.</ref>

Subsequent generations of cables carried telephone traffic, then [[data transmission|data communication]]s traffic. These early cables used copper wires in their cores, but modern cables use [[optical fiber]] technology to carry [[digital data]], which includes telephone, Internet and private data traffic. Modern cables are typically about {{convert|25|mm|in|0|abbr=on}} in diameter and weigh around {{convert|1.4|t/km|ST/mi LT/mi|abbr=off}} for the deep-sea sections which comprise the majority of the run, although larger and heavier cables are used for shallow-water sections near shore.<ref>[https://web.archive.org/web/20160526231647/http://www.techteledata.com/how-submarine-cables-are-made-laid-operated-and-repaired/ "How Submarine Cables are Made, Laid, Operated and Repaired"], TechTeleData</ref><ref>[http://image.guardian.co.uk/sys-images/Technology/Pix/pictures/2008/02/01/SeaCableHi.jpg "The internet's undersea world"] {{webarchive|url=https://web.archive.org/web/20101223170755/http://image.guardian.co.uk/sys-images/Technology/Pix/pictures/2008/02/01/SeaCableHi.jpg |date=2010-12-23 }}&nbsp;– annotated image, ''The Guardian''.</ref>