Continuous, traveling coupling between seismic waves and the ionosphere evident in May 1968 Japan earthquake data

Seismic, atmospheric, and ionospheric data collected at Japan and Hawaii after the May 16, 1968, Hachinohe, Japan, earthquake have been analyzed and compared. They show that earth-quake-generated seismic waves produced upward-traveling acoustic waves that propagated over a large front and penetrated into the atmosphere to at least 300 km, producing oscillatory disturbances there. Comparison of the spectra of the acoustic waves at two heights indicates that the shorter-period oscillations (about 20–25 seconds) were more severely attenuated with height than the longer-period oscillations (about 2 minutes). Theoretically obtained values of pressure oscillations are in good agreement with those derived from the experimental Doppler records.