The web of undersea cables that transmit data all over the world can one day be used to track tsunamis and earthquakes, according to new research.One of Google’s fiber-optic cables was able to successfully pick up on earthquakes nearby through detecting distortions in light pulses along the cable.
“Can we find a less expensive way to cover the ocean with geophysical sensors? There’s already this telecommunication cable infrastructure out there. If you can turn them into sensors, that’s wonderful — and that’s what we’re doing now,” says Zhongwen Zhan,an assistant geophysics professor at the California Institute of Technology.
The new approach capitalises on what the cables are already designed to do. When a transmitter at one end of the cable sends out a light signal transmitting data, light waves are oriented in a particular direction. If an earthquake hits, it might shake, bend, or twist the cable — and that changes the orientation of the light waves. At the other end of the cable, Google notices distortions and corrects them. Now, it wants to share its data, changes to what’s called the “state of polarization” of light, with seismologists like Zhan so they can study the earthquakes that caused the distortions.
“We’re humbled and excited by the possibility of collaborating with the optical, subsea and seismic research communities to use all of our cable infrastructure for greater societal benefits,” Google said in a blog.
