Two separate fiber cuts on the SHEFA-2 cable that connects the Faroe Islands to Scotland via the Shetland Islands took most of communications on the islands offline on 20 October 2022. Services were restored the next day, per a BBC report.
https://www.bbc.com/news/uk-scotland-north-east-orkney-shetland-63337473
SHEFA-2 ("SHEtland-FAroes") is run by SHEFA, a 100% owned subsidiary of Faroese Telecom. SHEFA-2 was put into service in 2008, replacing an earlier SHEFA-1 which dated from 1971.
SubmarineCableMap.com has a detailed map, listing landing points at Maywick and Sandwick.
https://www.submarinecablemap.com/submarine-cable/shefa-2
BBC Radio Shetland is the broadcaster to the archipelago, and its evening broadcast of the 20th of October has an account of the impact on the 23,000 residents there. Phone service, internet service, automatic teller machines, and access to emergency services were all affected.
https://www.mixcloud.com/BBCShetland/good-evening-shetland-thursday-20th-of-october-2022/
In the case of a single fiber cut, there is redundancy, in the sense that traffic from Shetland has an alternate return path via the Faroe and the FARICE-1 cable. But there are only two ways out, and if both of them are offline.
Subsea cables go out of service with some regularity. Fishing trawlers which tow nets at the very bottom of the ocean will snag a cable, and this is a suspected cause of the Shetland incident. Other natural causes for outages include earthquakes and the associated submarine landslides that can wreck service. Submarine Telecoms Forum tracks these outages, which have affected diverse cables such as PPC-1 (Papua New Guinea), IMEWE (Egypt), Greenland Connect (Greenland), SEAMEWE-5 (Pakistan), and APG (Vietnam) in the past few months.
https://subtelforum.com/category/cable-faults-maintenance/
A more sinister threat to subsea cables is deliberate damage by military interests. The UK government cut off Germany's submarine telegraph cables in 1914 during World War I, which forced German communications onto the worldwide British network where they could be more easily intercepted and decoded.
https://www.bbc.com/news/world-europe-42367551
Since then the cable network has vastly expanded, but the threat is still there. And while there's no indication that the Shetland incident on SHEFA-2 is anything other than a routine failure, policy makers have recently raised an alarm of recent Russian activity in mapping the cable network.
