Damaged Undersea Cable Could Keep Tonga Offline for Weeks Following Volcanic Eruption

Damaged Undersea Cable Could Keep Tonga Offline for Weeks Following Volcanic Eruption
Volcanic ash covers rooftops and vegetation in a photo taken Jan. 17, 2022, following a volcanic eruption in Tonga. (Photo: Vanessa Parker/NZDF, AP)

Critical aid is just now making its way to Tonga nearly five days after an earth-shaking volcanic eruption rattled the small Pacific island nation. And while telephones service and other basic communication are starting to slowly come back online, a major disruption to an undersea fibre-optic table could leave residents disconnected from the internet for weeks.

Tonga is digitally connected to the outside world via a single submarine fibre optic cable linking the nation to neighbouring Fiji. The 830-kilometre cable, managed by Tonga Cable Ltd., likely broke during the tsunami that followed the volcanic eruption. It now awaits repairs from a Papua New Guinea-based specialised ship, which is still around eight days away. Once the ship finally arrives, repair specialists will still have to determine the precise location of the damage, no easy task since the cable must be retrieved from the dark depths of the ocean floor.

Repair workers, MIT Technology Review notes, often determine the approximate location of a break by shining a light down one end of a fibre-optic core and calculating how long it takes for that signal to bounce back. All told, the island nation likely won’t see internet access restored for another two to four weeks, a nightmare complicating an already challenging humanitarian relief effort. The cable repair ship will also have to line up with aid vessels looking to provide other critical resources to Tonga residents impacted by ashfall that’s destroyed houses and contaminated drinking water.

A recent blog post from web infrastructure company Cloudflare provides more details surrounding the outage’s timeline and impact. According to Cloudflare, massive internet outages were detected in the late afternoon the day after the eruption.

At the same time, Cloudflare did not detect any similar internet disruption in relatively nearby Fiji or American Samoa. Tonga Cable Limited, the firm overseeing the cable, reportedly found two faults in the cable, one 37 kms from the island’s capital and another 47 kms away.

This also isn’t the first time Tonga has plunged into internet isolation due to a damaged cable. The nation experiences a near-total blackout of internet and mobile services in 2019, according to the BBC. That outage was reportedly caused by a ship dropping anchor and unintentionally severing the cable, a little mishap that cost the Tongan government around $277,640 to repair. The costs to repair the current damage are TBD, but the rush job could be costly. Doug Madory, the director of internet analysis for monitoring firm Kentik, told MIT Technology Review that countries generally “pay a little premium to get fixed first.”