New research led by Britain’s National Oceanography Centre (NOC) has found that the greatest risks to subsea telecommunications cables lie close to island coastlines.
A study jointly led by Dr Isobel Yeo and Dr Mike Clare at the NOC provides “the first global assessment focused specifically on the resilience of subsea telecommunications connections for small islands”.
The research published in the International Journal of Disaster Risk Reduction analysed more than 5,000 subsea cable faults recorded globally over the past 40 years. It combined this with spatial analyses of environmental and human hazards across 24 islands or island groups in the South Pacific, Caribbean and Indian Ocean regions.
The study found that more than 75% of recorded faults on island-connecting cables occur within 300 km of island coastlines, “highlighting nearshore regions as key areas of vulnerability and priority locations for resilience planning, monitoring and investment”.
Subsea telecommunications cables form the backbone of the global internet, carrying more than 99% of international digital data traffic. For many island nations, a single cable connection can support almost all international communications, internet access, banking systems, healthcare services, tourism operations and emergency response communications, the authors state.
The study identified strong links between cable faults and human activity exposure, particularly in nearshore waters where fishing, anchoring and coastal activity are concentrated.
However, the research also found that natural hazard exposure does not always translate directly into more frequent faults, suggesting that engineering design, route selection, and operational planning can significantly reduce risk under normal operating conditions. The research forms part of the NOC's wider ongoing work to improve understanding of marine geohazards and risks to subsea infrastructure, including submarine landslides, volcanic eruptions, turbidity currents, and the resilience of seafloor cable systems.
