Tonga communications could be down for "weeks" following volcanic eruption

Tonga’s subsea internet cable has been damaged after a volcanic eruption, which could leave the island without internet access for "weeks".

The undersea Hunga Tonga-Hunga Ha’apai volcano erupted on 15 January, causing a 1.2-metre tsunami wave to hit the island nation of Tonga. The volcano is located around 65km north of Tonga’s capital, Nuku'alofa.

Southern Cross Cable has confirmed in a Facebook post that the Tonga Cable has been cut approximately 36km from the island nation. It added that Tonga Cable Limited is working with Subcom, the South Pacific Maintenance authority, to arrange repairs.

Digicel, local telco and a minority stakeholder of the cable, confirmed that its customers in the country have experienced disruption in their mobile service too. It added that all communication to the outside world in Tonga is affected due to the damage to the Tonga Cable as a result of the volcanic eruption.

The company is working to get its satellite link connectivity which will be available to limited customers in essential services and government.

The repair is likely to be carried out by a cable laying vessel called the CS Reliance which is currently near the Papua New Guinea capital of Port Moresby, around 4,000km away, according to the NZ Herald. The ship is operated by Subcom which holds a maintenance contract covering 19 cable systems across the South Pacific.

“SubCom has a long-standing marine maintenance contract in the South Pacific region and is actively working with the customer to mobilise cable ship SubCom Reliance for the Tonga cable repairs, while evaluating crew and ship safety in the affected area," a spokesperson from the company told IT Pro.

Samiuela Fonua, Tonga Cable director, told the NZ Herald that the last cable cut took nearly two weeks to repair.

"This time, I am not sure yet because we have to take into account site conditions, the fact that the repair ship will be entering the Tongatapu waters not too far away from the eruption site - and if the volcano is still active."

Tonga currently has limited phone and internet access, as Fonua said that the dust cloud from the volcano was interrupting satellite communications.

New Zealand telcos Spark and Vodafone NZ are offering free mobile and landline calls to Tonga this week.

This isn’t the first time the Tonga Cable has been cut off from the internet, as in 2019 the undersea cable was severed twice, according to a ZDnet report. The island nation went without a working subsea cable for two weeks and had to rely on satellite providers for its internet connection. The 827km cable between Tonga and Fiji connects to the Southern Cross Cable that was launched in 2013, and was funded jointly by the Asian Development Bank and the World Bank.