New Scientist by Donna Lu 11/28/2019
Fibre-optic cables are good for speedy downloads – and for detecting earthquakes.
Nathaniel Lindsey at the University of California, Berkeley, and his colleagues temporarily turned 20 kilometres of existing underwater fibre-optic cables into a row of seismic sensors along the floor of the Pacific Ocean.
The researchers recorded a 3.5-magnitude earthquake and discovered a new fault system off the coast of California.
Fibre-optic cables transmit information in the form of light. An extensive underwater network of these cables connects all the continents except Antarctica and transmits telecommunications data, including telephone and internet traffic.
The researchers used a technique called distributed acoustic sensing, which works by sending pulses of light through the cable and analysing the light that returns to detect slight movements.
“If you start moving a certain portion of the fibre because there’s some seismic wave propagating, you’ll be able to see that seismic wave strain on the cable,†says Lindsey.
More:
https://www.newscientist.com/article/2224901-underwater-internet-cables-can-detect-offshore-earthquakes/
