Researchers at Pennsylvania State University have developed a method that uses standard fibre-optic internet cables to detect underground hazards like sinkholes, offering a cost-effective early warning system for geohazards.
PENNSYLVANIA: In a breakthrough that could redefine how scientists monitor underground hazards, researchers at Pennsylvania State University have found that ordinary fibre-optic cables — the same ones used to transmit internet data — can detect geohazards such as sinkholes and subsurface fractures well before they become visible on the surface.
The study, published in the Journal of Geophysical Research: Solid Earth, details how the team applied acoustic sensing technology to pre-existing communication cables buried only a few feet underground. By connecting a Distributed Acoustic Sensing (DAS) device to a four-mile stretch of fibre-optic cable, they were able to send light signals that captured subtle acoustic changes across the line’s entire length.
“These everyday traffic vibrations that we once dismissed as noise are actually valuable data sources,” said Tieyuan Zhu, associate professor of geophysics and co-author of the paper. “Our research shows that what we used to consider ‘garbage noise’ can help identify underground anomalies affordably and efficiently.”
Unlike conventional geophones, which are expensive and collect data from single points, the new technique transforms everyday vibrations — such as those from cars or footsteps — into seismic surface waves through cross-correlation analysis. This process creates a dense network of data points, producing detailed maps that show areas of ground instability hundreds of feet below the surface.
The researchers say that with minimal modification, this technique could turn the global network of fibre-optic communication cables into a massive, real-time early warning system for sinkholes, earthquakes, and other geohazards — potentially saving lives and infrastructure worldwide.
