Thunderquakes make underground fiber optic telecommunications cables hum

Science Daily  December 11, 2019
Researchers at Pennsylvania State University report on a distributed acoustic sensing (DAS) array using preexisting underground fiber optics beneath the Penn State campus for detecting and characterizing thunder‐induced ground motions. During a half‐hour interval in State College, PA, they identified 18 thunder‐induced seismic events in the DAS array data. The high‐fidelity DAS data show that the thunder‐induced seismic are very broadband, with their peak frequency ranging from 20 to 130 Hz. The dense DAS data enable them to simulate thunder‐seismic wave propagation and full waveform synthetics and further locate the thunder‐seismic source by time‐reversal migration. DAS is positively correlated with National Lightning Detection Network lightning current power. These findings suggest that fiber‐optic DAS observations may offer a new avenue of studying thunder‐induced seismic, characterizing the near‐surface velocity structure, and probing the thunder‐ground coupling process. The researchers reported this at the 2019 Fall AGU meeting…read more. TECHNICAL ARTICLE