Thunder-induced seismic waves map hidden hazards beneath university campus

Scientists at Penn State, headed by geophysicist Tieyuan Zhu, examined a dataset spanning two and a half years of seismic signals picked up by fiber-optic cables laid beneath the University Park campus in State College, Pennsylvania. The cables, originally installed for telecommunications, act as sensors that detect minute ground motions caused by thunder-generated acoustic waves, known as thunderquakes. By processing more than 450 of these events, the researchers generated detailed images of the near-surface geology down to roughly 100 meters, uncovering previously unknown weak zones in the karstic limestone that may lead to future sinkholes.

Validation came from borehole records and satellite-derived surface deformation measurements. The authors argue that such thunder-driven surveys could be a cheaper, wide-area alternative to traditional seismic methods, especially where fiber networks already exist, and even propose potential applications on other planets like Titan. The findings were published in Science Advances on August 21.