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Infrasound from thunder: A natural seismic source
Author(s) -
Lin TingL.,
Langston Charles A.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl030404
Subject(s) - thunder , seismology , geology , seismometer , seismogram , borehole , amplitude , rayleigh wave , slowness , waveform , seismic wave , surface wave , sonic logging , infrasound , geophysics , acoustics , meteorology , geotechnical engineering , physics , optics , quantum mechanics , voltage
A small array consisting of five three‐component short‐period surface seismometers, a three‐component borehole seismometer, and five infrasound microphones was built to investigate thunder‐induced ground motions. Data from two thunder events with similar N‐wave waveforms but different horizontal slownesses are chosen as examples of data collected by the array. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters at the site. Although the depth of the borehole is relatively shallow compared to a seismic wave wavelength, velocity amplitude in the radial component decays as much as 63 percent with depth but vertical component amplitudes are unaffected consistent with air‐coupled Rayleigh wave excitation. Naturally occurring thunder appears to be a useful seismic source to empirically determine site resonance characteristics for hazards assessments.