Fiber-optic networks detect underground hazards before damage occurs

Penn State researchers mapped hidden subsurface risks using thunderquake signals in existing cable infrastructure

Penn State researchers analyzed 450 thunderquakes over 2.5 years of data from fiber-optic cables buried 1 meter underground at a Pennsylvania campus. The technique mapped subsurface geology down to 100 meters depth, identifying previously undetected weak zones in limestone formations at the site. Published in *Science Advances* on August 21, 2026, the method uses existing fiber-optic networks to create images of shallow subsurface hazards. This approach could reduce costs for urban areas with established cable infrastructure by avoiding traditional seismic surveys. The campus landscape is karstic (limestone-based), and findings were corroborated using surface deformation data.

This technique offers early warnings for underground hazards before they cause damage, potentially preventing costly disaster response. However, it is limited to 100 meters depth, tested only on karstic limestone terrain, and requires existing fiber-optic networks. Its applicability to other geological formations remains unverified. The source provides no claims of disaster prevention—only hazard detection and early warning capability.

Source: Science News