Undersea cables carry internet traffic across continents. They are part of the critical information infrastructure of the modern world.
Scientists started using these cables as a global network of sensors that monitor seismic and other changes at the seabed, previously beyond the reach of the scientific community.
As Wired indicated in the recent coverage
Where there’s cable, there’s potential data.
Undersea cables could also be used as early-warning tools for earthquakes and tsunami as they can detect any tectonic shifts on the seabed.