Cable Quakes

Fiber optics that connect the world can detect its earthquakes, too

- -Saugat Bolakhe

THE SAME OPTIC FIBERS that pulse with the world’s Internet traffic are now listening to the pulse of the planet, picking up earthquake tremors in better detail than traditional seismic networks do.

In a recent Science study, researchers used 15 kilometers of telecom fiber near Mendocino, Calif., to record the region’s biggest earthquake in five years—capturing in fine detail how the magnitude 7 rupture started, slowed and sped up, accelerating even faster than the speed of sound.

“This is almost as if you look at Saturn and say, ‘That’s a star.’ Then, you are given a new telescope and suddenly realize, ‘Oh, my God, there’s actually a ring around it!’” says Zhongwen Zhan, a geophysicist at the California Institute of Technology, who was not involved in the study.