How one of Google’s massive undersea cables detects earthquakes - The Verge

Feb 25, 2021

The web of undersea cables that transmit data around the world could one day be used to track earthquakes and tsunamis, according to new research.

During a test run last year, one of Google’s fiber-optic cables was able to successfully pick up on nearby earthquakes by detecting distortions in light pulses sent along the cable?

On top of their main job of sending data all over the world, these cables could one day send early warnings to people on shore when a tsunami is barreling their way.

The novel approach doesn’t even require installing any new equipment to the existing web of more than a million kilometers of fiber optic cables that cut across the seafloor.

Beyond having a better view of the ocean than the small number of existing sensors specifically designed to look for tsunamis, fiber optic cables can also send warnings to shore much faster — perhaps in a matter of milliseconds, according to Google.

In 2018, similar research was published that showed that seafloor cables had the potential to detect earthquakes and tsunamis — but that approach came with some limitations.