Researchers at Penn State used a 4‑kilometer fiber‑optic cable on campus to record seismic waves produced by summer thunderstorms and applied the data to construct a model of the Earth’s surface. Seismic waves generated by thunderclaps travel through varied materials, creating Rayleigh waves that move along the surface and deeper body waves that propagate through soil and rock. Understanding these waves requires modeling how energy is transmitted across different geological layers. The team employed SPECFEM3D, a three‑dimensional seismic wave simulation package. The software approximates the atmosphere as a uniform 3.6‑km layer and updates events at a rate slower than wave motion. To improve alignment with ground motion, the researchers expanded the model’s near‑surface layer from 20 m to 200 m. The model was validated by comparing simulated wave patterns with measurements collected during actual thunderstorms on the campus fiber line. The comparison indicated that the approximation captured key features of the observed seismic signals. The approach leverages existing telecommunications infrastructure to obtain seismic data without deploying dedicated sensors, offering a potentially cost‑effective method for geological research. The technique may enable future surface‑structure studies, and further validation across diverse geological settings will be needed to assess its broader applicability.