Scientists turned a massive underwater internet cable into a 2,700-mile-long microphone that listens to the entire ocean.
March 18, 2026
Original Paper
High-Resolution Trans-Oceanic Distributed Acoustic Sensing Enabled by a Bi-Directional Sensor Implementation
arXiv · 2603.15828
The Takeaway
By sending laser pulses down existing trans-oceanic fiber optic cables, researchers can detect tiny vibrations from earthquakes or whales across an entire ocean basin. This effectively turns the global network of internet cables into a massive seafloor observatory without laying any new equipment.
From the abstract
We demonstrate continuous distributed acoustic sensing over a 4400km long undersea cable. Bi-directional operation improves the strain signal-to-noise rate by >20dB, enabling 88000 50-m-spaced measurement points at a nominal telecom launch power.