A lone undersea internet cable connected Tonga to the world – a volcanic eruption broke it
The Effects of a Colossal Volcanic Eruption in Tonga’s Pacific Archipelago are still being calculated, but one consequence is clear: Tonga has been cut off from the internet after the lone submarine cable connecting the country to the rest of the web was damaged in the eruption.
Like many island nations, Tonga relies on just a single submarine cable, about the thickness of a garden hose and filled with fragile fiberglass filaments, to get citizens online. But on Tuesday, the government of Tonga said “communications both international and domestic were cut as a result of damage sustained by the submarine cable.”
The government added that “limited communications” were possible via satellite phones and high-frequency radio, but these limitations make it difficult to assess the damage caused by the January 14 eruption. The Tongan government has reported three fatalities from a tsunami created by the volcano, which erupted on an uninhabited island.
According to Reuters, the internet cable connecting Tonga to the web is 827 kilometers long and secured via a relay in Fiji, Tonga’s second-closest neighbor. Repairing the cable can take up to two weeks as the work requires the intervention of a specialized submarine cable repair vessel.
The closest ship is the Reliance, owned by the American company SubCom. But it is currently moored some 4,700 kilometers (2,920 miles) away in Papua New Guinea, and it will take days to travel to Tonga. According to Craige Sloots, director of marketing and sales at Southern Cross Cable Network, a company that maintains a number of submarine cables in the region, that means it could take up to two weeks in total to fix Tonga’s internet connection.
“The ability to repair would also depend, as you would expect, on volcanic activity,” Sloots told Reuters.
The incident is a vivid demonstration of the fragility of the modern internet. Although we think of the web as a dense network with numerous redundancies, the truth is that it contains many single points of failure. In the West, this is most apparent when massive internet outages are caused by disruptions to centralized services like Amazon Web Services – an Amazon subsidiary that provides servers and computing power to the world’s largest companies.
For countries like Tonga, however, submarine cables are a more obvious bottleneck. Currently, 99 percent of international internet traffic goes through such submarine cables, with a estimated 436 cables over distances of 1.3 million kilometres. But while countries like the US are served by multiple lines, poorer countries like Tonga depend on just one.
It is noteworthy that Tonga was actually hit by a similar internet outage in 2019, and as a result signed a 15-year deal with an internet satellite company protect against future failures. But according to a report by ZDNet, the terms of the contract with provider Kacific were disputed and as a result, the satellite link was never activated.
Now Tongans have to wait for their internet to be fixed by hand. Such repairs are not uncommon on a global scale—a submarine cable break about every two weeks – but they are time consuming. Technicians from a specialist repair vessel will have to locate the fault in Tonga’s cable by sending pulses of light down the line and determining how long it takes for the pulse to return. They will then have to sail to the site of the break and, depending on the depth of the water, retrieve the cable with diving robots or grappling hooks. The cable is then brought to the surface and repaired by technicians on board the vessel.