The Irish technology being used to track Russian submarines

February 22, 2026 - 17:43

A pioneering method developed by researchers at Trinity College Dublin is transforming standard subsea fibre-optic cables into a vast, sensitive network for tracking movement in the ocean's depths. The technology, which sends laser pulses through existing telecommunications cables, can detect everything from marine life to submarines, offering a novel tool for environmental science and security.

The system works by analyzing the tiny distortions in light signals caused by acoustic pressure waves underwater. When a vessel, such as a ship or submarine, passes near a cable on the seabed, it creates a unique acoustic signature that subtly alters the laser light. Sophisticated monitoring equipment at the cable's landing station can interpret these changes, pinpointing the location and movement of the object.

This breakthrough provides a potentially game-changing capability for monitoring undersea infrastructure and maritime borders. It offers a persistent, wide-area surveillance method without the need for deploying numerous dedicated sensors. Beyond security applications, scientists highlight its value for protecting marine ecosystems by tracking whale migrations and monitoring seismic activity. The technology turns the global network of communication cables into a giant, responsive ear on the seafloor, listening to the pulse of the ocean itself.