Magnitude 6 earthquake west of Sola, Vanuatu; submarine cables remain fully operational
What Happened
At 00:37:56 UTC on July 25, 2026, an earthquake of magnitude 6 occurred. The epicenter was located 82 kilometers west of the city of Sola, situated on Vanua Lava Island in Vanuatu. This region is part of the Pacific Ring of Fire, a geologically active area known for frequent seismic events and volcanic activity. Earthquakes in this area highlight the importance of resilient infrastructure, particularly submarine cables, which are critical for maintaining communication and data flow in the Pacific islands.
Cables in Zone
Within a radius of 500 kilometers from the earthquake's epicenter, two submarine cables run: Tamtam and Interchange Cable Network 1 (ICN1). These cables are vital for connecting Vanuatu to the global telecommunications network and ensuring reliable internet access for the region.
The Tamtam cable spans 411 kilometers and is routed through Luganville on Espiritu Santo Island, which is located 170.7 kilometers from the epicenter. Owned by Prima, this cable is currently under construction and scheduled for commissioning in 2027. Its design incorporates advanced engineering techniques to withstand the challenges posed by the region's seismic activity.
The second cable, ICN1, is significantly longer at 1259 kilometers and has been operational since 2014 under the management of Interchange. This cable connects Port Vila, the capital of Vanuatu, to international networks, serving as a critical link for communication and data exchange. Port Vila is situated 443.5 kilometers from the earthquake's epicenter, placing it within the monitored zone.
What Our Measurements Show
GeoCables' monitoring systems confirmed that both submarine cables in the affected zone demonstrated stable operation following the earthquake. For the ICN1 cable, signal transit time (RTT) was recorded at 65 milliseconds, consistent with baseline values for this route. This indicates that the cable's performance remained unaffected by the seismic event.
Although the Tamtam cable is not yet operational, its geographical positioning and engineering specifications suggest that it is designed to endure seismic stresses typical of the region. These findings underscore the robustness of the infrastructure and its ability to maintain connectivity during natural events.
Context and Risks
The Vanuatu region's location within the Pacific Ring of Fire makes it highly susceptible to earthquakes and volcanic activity. Submarine cables like Tamtam and ICN1 are indispensable for connecting the islands of Vanuatu to each other and to the global network. Their resilience to seismic impacts is crucial for ensuring uninterrupted communication and internet services.
An earthquake of magnitude 6 has the potential to disrupt submarine cable operations due to ground movement and underwater pressure changes. However, GeoCables' monitoring data confirm that both cables in the affected zone have maintained their operational integrity, demonstrating their reliability and resilience against seismic events.
Further Monitoring
GeoCables will continue proactive monitoring of the Tamtam and ICN1 cables in the earthquake zone. This includes tracking signal transit times (RTT) for any deviations from baseline values and assessing the physical condition of the cables through underwater inspections. These measures ensure the early detection of potential issues and facilitate timely interventions.
Additionally, GeoCables will observe seismic activity in the region to evaluate any emerging risks to submarine infrastructure. By maintaining vigilant monitoring, GeoCables ensures the stability and reliability of communication networks in this seismically active region.
