Thunderquakes map subsurface via fiber optics

Researchers from Pennsylvania State University and Ohio State University demonstrated that seismic waves generated by thunder, called thunderquakes, can be used to map the Earth's subsurface using existing fiber-optic cables. By applying distributed acoustic sensing to a 4-kilometer telecom cable in State College, Pennsylvania, they recorded 458 thunderquakes over two years. Analyzing air-coupled Rayleigh waves and seismic dispersion, they reconstructed subsurface properties down to 300 feet, identifying four weak zones consistent with fractures or voids, two of which coincide with subsiding areas. This technique offers a cost-effective, passive alternative to traditional seismic surveys, with potential applications in detecting groundwater, contamination, sinkholes, and evaluating building sites. The method could also be extended to other atmospheric sources like sonic booms and volcanic eruptions, and possibly to other planetary bodies such as Titan.