Each day during the month of April, the Institute will feature one of the 30 ‘perspectives’ from the One Ocean report. These short articles include a diverse range of views regarding oceans management in New Zealand. Enjoy!


Professor Lionel Carter, Professor at the Antarctic Research Centre, Victoria University of Wellington

Submarine cables

If you send an international email, use a search engine or make an overseas phone call, there is a 95 percent probability the communication will be via the global network of subsea fibre-optic cables. Why cables and not satellites? Put simply, cables transfer enormous amounts of data and voice traffic more rapidly, economically and securely than satellites. Such is society’s reliance on the global network, it is classed as critical infrastructure.

The United Nations Convention on the Law of the Sea (UNCLOS) foresaw this importance, and specified freedoms to lay and maintain cables with due regard to rights and laws of coastal states. Cables have minimal environmental impact and are primarily about the size of a garden hose in diameter. Thus the physical footprint is small. Glass fibres and electrical components are encased in marine-grade polyethylene that is chemically inert. These systems are laid on the seabed in water depths exceeding 1,500 metres, where they remain for up to 25 years unless they require repair. In shallower waters, cables are wrapped in wire armour and buried under the seabed for protection against fishing and shipping activities, which account for 70 percent of all breaks.

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