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Author ORCID Identifier
https://orcid.org/0009-0000-8343-6667
Date Available
7-13-2026
Year of Publication
2026
Document Type
Master's Thesis
Degree Name
Master of Science (MS)
College
Arts and Sciences
Department/School/Program
Earth and Environmental Sciences (Geology)
Faculty
Seth Carpenter
Faculty
Andrea Erhardt
Abstract
Tornadoes cause extensive property damage and endanger lives. While Doppler radar can indicate the potential for tornado development, it cannot confirm that a tornado is in contact with the ground unless a debris signature is present. While on the ground, a significant amount of a tornado’s energy may be transferred into the earth as seismic vibrations. Thus, seismometers have the potential to detect on-the-ground tornadoes. Since 1960, only five papers have published seismic recordings from tornadoes. These studies have mostly reported on seismic waves generated by tornadoes at a relatively large range, from 0.01-2.5 Hz, representing uncertainty in the dominant tornado seismic frequency. Furthermore, no previous work has attempted to validate previous findings through the analysis of the same tornado. To build on these previous studies and fill current knowledge gaps, this study’s primary objectives were (1) to identify tornado seismic signals (TSS) and characterize them by their dominant frequencies, (2) determine the dominant wave-types and forcing mechanisms; and (3) to quantify the thresholds at which TSS can be recorded based on distance and EF rating. In this study, seismic data from five tornadoes including one EF1, three EF4s, and one EF5 were analyzed, each passing within 10 km of at least one broadband seismic station. Seismograms were analyzed alongside meteorological data to isolate TSS from broader storm activity. Spectral methods, including spectrograms and power spectral densities (PSD), were used to identify dominant TSS frequency bands, and particle motion and polarization analyses were used to infer wave types and ground motion characteristics. Signal attenuation and detectability thresholds were assessed using PSDs calculated at various tornado-seismometer distances. Results showed that tornado passage consistently produced broadband seismic signals spanning 0.005–45 Hz. The most distinct band for TSS propagation was concentrated in the 0.5–10 Hz band, where the 1–6 Hz range showed enhanced coherency with infrasound, suggesting acoustic-ground coupling, and the 1-3 Hz band showed evidence of Rayleigh waves. Lower frequencies (0.005-0.01 Hz) were apparently dominated by pressure-induced ground tilt, while intermediate frequencies (0.01-0.05 Hz) reflected mixed contributions from tilt and possible surface-wave excitation. Detection limits were strongly dependent on both distance and EF rating, with measurable TSS generally confined within ~4-7 km for an EF1 tornado but possibly extending to 20 km for an EF5 tornado.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2026.348
Archival?
Archival
Funding Information
This study was supported by the Federal Emergency Management Agency through grant DR-4630-KY.
Recommended Citation
Thompson, Seth, "IDENTIFICATION AND CHARACTERIZATION OF TORNADO SEISMIC SIGNALS IN THE CENTRAL U.S." (2026). Theses and Dissertations--Earth and Environmental Sciences. 127.
https://uknowledge.uky.edu/ees_etds/127
