Seafloor cables reveal hidden earthquakes in the Pacific

A groundbreaking international collaboration has successfully detected multiple earthquakes in the Pacific Ocean using an innovative optical sensing technique on undersea cables. Scientists from the National Physical Laboratory (NPL) in the UK and the Measurement Standards Laboratory (MSL) in New Zealand have repurposed part of the Southern Cross Next seafloor cable, which links New Zealand and Australia, to serve as a seismic and oceanic monitoring system.

This cutting-edge approach employs ultra-stable optical interferometry, using the fibre optics inside the cable to capture seismic and environmental data from the ocean floor - an area where traditional monitoring stations are absent. Since initiating measurements in October 2024, researchers have recorded over 50 earthquakes, with epicentres located between tens and hundreds of kilometres from the cable. The high detection rate marks a significant advancement in seismic research, refining the technique previously trialled in the less active Atlantic Ocean.

The research team will continue data collection until December 2025, aiming to develop a global network of subsea sensors leveraging existing cable infrastructure. As over 70% of the Earth’s surface is covered by water, and much of the ocean floor remains unmonitored, this technology could bridge critical data gaps in seismology, oceanography, and climate research.

Experts at GNS Science in New Zealand are assessing the technology’s potential for tsunami detection, exploring how it can complement existing monitoring methods. Improved seismic detection could enhance early warning systems, particularly benefiting coastal communities in earthquake-prone regions across the Pacific.

This pioneering project is supported by the UK’s International Science Partnership Fund and New Zealand’s Quantum Technologies Aotearoa programme.

Giuseppe Marra, Principal Scientist at NPL, emphasised the significance of the breakthrough: “This is the first time this technology has been tested in the Pacific, an ideal environment for demonstrating its potential for earthquake and tsunami monitoring. The success of this UK-NZ collaboration paves the way for future international partnerships.”

Dean Veverka, CTO of Southern Cross Cables Ltd, highlighted the real-world impact: “Natural disasters continue to challenge Pacific communities. Early earthquake detection will be crucial in protecting lives and livelihoods.”

British High Commissioner to New Zealand, Iona Thomas, praised the project as a model of international scientific cooperation: “The UK and New Zealand are leading in technological innovation. This initiative strengthens our collaboration and has the potential to drive transformative benefits across the Pacific.”

Annette Koo, Director of MSL, noted: “By integrating global expertise and advancing scientific frontiers, we are unlocking new ways to safeguard communities and better understand our planet.”

Bill Fry, Seismo-tectonophysicist at GNS Science, underlined the significance of the findings: “Enhancing seismic monitoring with undersea cable data could provide more rapid and accurate tsunami warnings, ultimately saving lives across the Pacific.”

This project marks a significant step in harnessing telecommunications infrastructure for environmental monitoring, reinforcing the role of science and technology in disaster preparedness and resilience-building across Asia-Pacific.

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