Undersea mudslide caused continent-wide internet outages

02 July 2021

A new study has found that two subsea cables off west Africa were severely damaged by undersea mudslides, which may have been linked to nearby river flooding.

In January 2020, the south Atlantic 3/West Africa (SAT-3/Wasc) cable, linking Africa to Portugal and Spain was hit by a breakdown in Gabon, whilst the West Africa Cable System (WACS) that connects South Africa to the United Kingdom saw an outage off the coast of the DRC Congo.

Later, in March, the WACS cable experienced a further break affecting international bandwidth.  Whilst many ISPs suffered extended outage periods, most of the major mobile operators were able to mitigate the impact on internet traffic due to their redundancy measures and were in a position to redirect data traffic to other subsea cable networks.

A yet-to-be-peer-reviewed study by Professor Peter J. Talling and a team from the Departments of Earth Sciences and Geography at the University of Durham in the UK, co-led by Angola Cables, suggests the events were caused by large undersea mudslides.

“The cable fault on the SAT-3 was likely caused by an exceptionally large and powerful submarine mud slide that originated at the mouth of the Congo River, just 10 days after the Congo River recorded its largest flood since the 1960s,” according to the press release.

It is hoped that the results of the study could help engineers build more resilient cable systems.