UNIVERSITY PARK, Pa. — Thunderstorms may be more than dramatic displays of light and sound. According to a new study led by Penn State researchers, the powerful acoustic waves generated by thunder can briefly shake the ground strongly enough to reveal hidden structures beneath Earth’s surface. The researchers have used these storm-generated vibrations, which they call “thunderquakes,” to produce a seismic image of the shallow subsurface, opening a potentially low-cost and widely available new source for geophysical research.
The study, published in Science Advances, demonstrates the first successful seismic imaging experiment based on thunderstorm-generated seismic waves. Instead of relying on earthquakes, controlled explosions or heavy equipment, the researchers captured the passage of thunder-induced energy through the ground using distributed acoustic sensing, or DAS. The technique transforms existing fiber-optic telecommunications cables into dense arrays of seismic sensors, allowing scientists to monitor subtle changes in the cable as waves travel through the Earth.
“Thunder generates atmospheric acoustic waves that couple into the ground, producing seismic signals,” said Tieyuan Zhu, associate professor of geosciences at Penn State and the study’s corresponding author. “We demonstrated the first successful seismic imaging using thunderquakes.” Zhu said the work not only establishes thunder as a possible seismic source for tomography, but also offers a new way to observe the complex interaction between the atmosphere and the solid Earth.
Thunder begins with an explosive expansion of air caused by lightning. The electrical discharge rapidly heats the surrounding atmosphere, creating a high-pressure shock wave that propagates outward as sound. Although most of the energy is heard as thunder, part of the atmospheric wave reaches the surface and transfers energy into the ground. At the boundary between air and soil, this transfer is affected by the angle of incidence, the strength and frequency of the acoustic wave, and the physical properties of the surface. The resulting ground motion is usually extremely small, but sensitive enough to be detected by modern fiber-optic sensing systems.
To record these signals, the Penn State team used an approximately 2.5-mile telecommunications fiber-optic cable buried a few feet beneath the University Park campus. The cable was not installed as a scientific instrument; it was existing communications infrastructure. Researchers sent laser light through the fiber and analyzed tiny changes in the phase of light scattered back toward the instrument. When seismic waves strained the cable, even by microscopic amounts, they altered the returning light. Those changes could then be converted into measurements of ground motion along the entire length of the fiber.
Unlike conventional seismometers, which record motion at individual locations, DAS can provide thousands of closely spaced measurement points. In the Penn State experiment, the system collected hundreds of samples per second at intervals of only a few meters. This high spatial and temporal resolution allowed the researchers to follow the thunder-generated signal from the atmosphere to the ground and then through the shallow subsurface. The dense observations were especially important because atmospheric acoustic waves and seismic waves behave differently, and their interaction can be difficult to separate with sparse instruments.
“Without incredibly high-resolution sensing, it’s difficult to actually piece together what’s going on when the thunder hits the ground,” said lead author Nolan Roth, who carried out the work during his doctoral studies at Penn State and is now a postdoctoral researcher at The Ohio State University. He explained that DAS enabled the team to observe the transition between an atmospheric source and a seismic signal in detail that had not previously been available in thunder studies.
The researchers used the recorded waves for seismic tomography, a technique that infers underground structure from the way seismic energy travels through it. Seismic waves move at different speeds depending on the density, elasticity, composition and layering of subsurface materials. By analyzing the arrival times and wave characteristics at many points along the cable, scientists can construct an image of the shallow Earth. Variations in the resulting image may reveal changes in soil, rock, fractured zones, buried geological boundaries or other features that cannot be directly seen from the surface.
Traditional seismic imaging can require expensive active sources, large teams and equipment that must be deployed across a study area. Passive seismic surveys, meanwhile, often depend on earthquakes or other naturally occurring events and work best where such sources are frequent. Thunderstorms offer a different option, particularly in regions such as the central and eastern United States where earthquakes are less common. Because storms occur across broad areas and existing fiber networks extend through cities, campuses and remote corridors, thunderquakes could provide a complementary source for near-surface imaging without major construction or environmental disturbance.
The approach could eventually support investigations of sinkholes, landslides, groundwater systems, mining areas, volcanic structures and other geohazards. Fiber-optic cables may also make seismic monitoring possible in locations where conventional instruments are difficult to install, including heavily regulated urban environments and remote polar regions. The method is not a replacement for earthquakes or controlled seismic sources: thunder varies in strength, location and frequency, and the atmosphere-ground coupling is complex. Researchers must also distinguish thunder signals from traffic, machinery, footsteps and other sources of noise. Nevertheless, the study shows that weather itself can provide usable energy for probing the planet.
The findings also carry implications beyond Earth science. Atmosphere-surface coupling is relevant to meteorology, geophysics and planetary exploration, where scientists seek to understand how gases, landscapes and solid planetary interiors interact. Earth’s atmosphere provides a natural laboratory for studying these processes, while future instruments on the Moon, Mars or other worlds may need unconventional seismic sources because their internal activity is poorly understood. The Penn State researchers now hope to test the method across a wider region along the East Coast, where changing weather patterns could generate a much larger collection of thunderquake observations. If successful, a network of ordinary fiber-optic cables could become an enormous, always-present sensor for both storms above and structures below.
Subject of Research: Not applicable
Article Title: Imaging Earth’s subsurface with thunderstorm-generated seismic waves
News Publication Date: 21-Aug-2026
Web References: https://doi.org/10.1126/sciadv.aeg8096; https://www.geosc.psu.edu/alumni/stay-connected/issue/20191/article/fiber-optic-environmental-senseing-foresee-project; https://www.psu.edu/news/earth-and-mineral-sciences/story/fiber-optic-cables-could-act-early-warning-system-geohazards-study
References: Science Advances, DOI: 10.1126/sciadv.aeg8096; U.S. National Science Foundation Award 2322198
Keywords: thunderquakes, thunderstorm-generated seismic waves, distributed acoustic sensing, DAS, seismic tomography, fiber-optic cables, subsurface imaging, geophysics, atmospheric acoustic waves, Penn State, seismic monitoring, geohazards
