Editing Submarine communications cable (section)

=== Technical perspective ===

==== Technical vulnerabilities ====
The remoteness of these cables in international waters, poses significant challenges for continuous monitoring and increases their attractiveness as targets of physical tampering, [[data theft]], and service disruptions.<ref name=":4" />

The cables' vulnerability is further compounded by technological advancements, such as the development of [[unmanned underwater vehicle]]s (UUVs), which enable covert cable damage while avoiding detection.<ref name=":16">Wrathall, L. R. (2010). The vulnerability of subsea infrastructure to underwater attack: Legal shortcomings and the way forward. ''San Diego International Law Journal'', ''12''(1), 223–262. <nowiki>https://digital.sandiego.edu/ilj/vol12/iss1/8</nowiki></ref> However, even [[Low technology|low-tech]] attacks can impact the cable's security significantly, as demonstrated in 2013, when three divers were arrested for severing the main cable linking [[Egypt]] with Europe, drastically lowering Egypt's [[Bandwidth (computing)|internet speed]].<ref name=":11" /><ref>{{Cite web |date=2013-03-27 |title=Egypt catches divers cutting Internet cable amid disruptions |url=https://www.reuters.com/article/technology/egypt-catches-divers-cutting-internet-cable-amid-disruptions-idUSBRE92Q1AQ/ |website=Reuters}}</ref> 

Even in shallow waters, cables remain exposed to risks, as illustrated in the context of the [[Korea Strait]].<ref name=":14">O’Malley, S. (2019). Assessing threats to South Korea's undersea communications cable infrastructure. ''The Korean Journal of International Studies'', ''17''(3), 385–414. https://doi.org/10.14731/kjis.2019.12.17.3.385</ref> Such sea passages are often marked as ‘maritime choke points’ where several nations have conflicting interests, increasing the risk of harm from shipping activities and disputes.<ref name=":5" />

Further, most cable locations are publicly available,<ref name=":5" /> making them an easy target for criminal acts such as disrupting services or stealing cable materials, which potentially lead to substantial [[Communications blackout|communication blackouts]].<ref name=":14" /><ref name=":17">Raha, U. K., & D., R. K. (2021). ''Submarine cables protection and regulations: A comparative analysis and model framework'' (pp. 1–177). Springer Nature. https://doi.org/10.1007/978-981-16-3436-9_1</ref> The stealing of submarine cable has been reported in [[Vietnam]], where more than 11 km of cables went missing in 2007 and were later presumed to be found on fishing boats, attributed to their incentives to sell them, according to media reports.<ref>Bdnews24.com. (2007, June 1). ''Vietnam's submarine cable lost and found''. Vietnam's submarine cable lost and found. https://bdnews24.com/bangladesh/vietnam-s-submarine-cable-lost-and-fou nd</ref><ref>Khan, A. S. (2007, June 2). ''Vietnam's submarine cable 'lost' and 'found' — LIRNEasia''. LIRNEasia. https://lirneasia.net/2007/06/vietnams-submarine-cable-lost-and-found/</ref>

==== Technical countermeasures ====
Typically, cables are buried in waters with a depth of less than 2,000 meters, but increasingly, they are buried in deeper seabed as a means of protection against high seas fishing and [[bottom trawling]].<ref name=":4" /><ref name=":7" /> However, this may also be advantageous against physical attacks from organized crime.

Further technical solutions are advanced protective casings,<ref name=":4" /> and monitoring them with, e.g., UUVs.<ref name=":11" /> Such technical solutions, however, can be challenging to implement and are limited in the remote areas of the high sea.<ref name=":4" /> Other proposed solutions include spatial modelling through protective or safety zones and penalties,<ref name=":19" /><ref name=":17" /><ref name=":16" /> increasing resources for surveillance,<ref name=":14" /> and a more collaborative approach between states and the private sector.<ref name=":1" /><ref name=":21">Hansen, S. T., & Antonsen, S. (2024). Taking connectedness seriously. A research agenda for holistic safety and security risk governance. ''Safety Science'', ''173'', 106436. https://doi.org/10.1016/j.ssci.2024.106436</ref><ref name=":3" /><ref name=":16" /> However, how to implement and enforce these solutions remains to be determined.<ref name=":17" /> The cables' remoteness thus complicates both physical attacks and their protection.

===== Cable repair =====
[[File:Submarine cable repair animation.gif|thumb|right|An animation showing a method used to repair submarine communications cables.]]

Shore stations can locate a break in a cable by electrical measurements, such as through [[spread-spectrum time-domain reflectometry]] (SSTDR), a type of [[Time-domain reflectometer|time-domain reflectometry]] that can be used in live environments very quickly. Presently, SSTDR can collect a complete data set in 20ms.<ref>Smith, Paul, [[Cynthia Furse|Furse, Cynthia]], Safavi, Mehdi, and Lo, Chet. "Feasibility of [http://livewiretest.com/analysis-of-spread-spectrum-time-domain-reflectometry-for-wire-fault-location/ Spread Spectrum Sensors for Location of Arcs on Live Wires] Spread Spectrum Sensors for Location of Arcs on Live Wires." ''IEEE Sensors Journal''. December, 2005. {{webarchive |url= https://web.archive.org/web/20101231231446/http://livewiretest.com/analysis-of-spread-spectrum-time-domain-reflectometry-for-wire-fault-location |date= December 31, 2010 }}</ref> Spread spectrum signals are sent down the wire and then the reflected signal is observed. It is then correlated with the copy of the sent signal and algorithms are applied to the shape and timing of the signals to locate the break.

A cable repair ship will be sent to the location to drop a marker buoy near the break. Several types of [[grapple (tool)|grapples]] are used depending on the situation. If the sea bed in question is sandy, a grapple with rigid prongs is used to plough under the surface and catch the cable. If the cable is on a rocky sea surface, the grapple is more flexible, with hooks along its length so that it can adjust to the changing surface.<ref>[https://books.google.com/books?id=TuQDAAAAMBAJ&pg=PA621 "When the ocean floor quakes"] ''Popular Mechanics'', '''vol.53''', no.4, pp.618–622, April 1930, {{ISSN|0032-4558}}, pg 621: various drawing and cutaways of cable repair ship equipment and operations</ref> In especially deep water, the cable may not be strong enough to lift as a single unit, so a special grapple that cuts the cable soon after it has been hooked is used and only one length of cable is brought to the surface at a time, whereupon a new section is spliced in.<ref>Clarke, A. C. (1959). ''Voice Across the Sea''. New York, N.Y.: Harper & Row, Publishers, Inc.. p. 113</ref> The repaired cable is longer than the original, so the excess is deliberately laid in a "U" shape on the [[seabed]]. A [[submersible]] can be used to repair cables that lie in shallower waters.

A number of ports near important cable routes became homes to specialized cable repair ships. [[Halifax Regional Municipality|Halifax]], Nova Scotia, was home to a half dozen such vessels for most of the 20th century including long-lived vessels such as the [[Cable Ship|CS]] ''Cyrus West Field'', CS ''Minia'' and ''[[CS Mackay-Bennett]]''. The latter two were contracted to recover victims from the [[sinking of the RMS Titanic|sinking of the RMS ''Titanic'']]. The crews of these vessels developed many new techniques and devices to repair and improve cable laying, such as the "[[Pipe-and-cable-laying plough|plough]]".