E Layer ionospheric disturbances following the Coalinga earthquake

Journal Article · Fri Jan 01 04:00:00 EST 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA01p00227· OSTI ID:5292852

Fitzgerald, T J; Wolcott, J H

In a previous report, Doppler shifts in HF radio transmissions through the ionospheric F region following the Coalinga, California earthquake of May 1983 were described. We report here on disturbances which appeared between 400 and 500 s after the earthquake as peaks or broad bands of enhanced power in the spectra of the HF transmissions and not as Doppler shifts. While the time delay (600--800 s) before the occurrence of the Dopppler shifts corresponds to the acoustic travel time to the F region. We believe that the occurrence of the spectral changes represents the presence of temporary E-region propagation modes induced by the passage of the acoustic waves responsible for the Doppler shifts observed at high altitudes. Because the enhanced spectral power occurs at negative frequency relative to that of the F-region propagation modes, the disturbances could be the result of reflections from electron density gradients induced by upwardly propagating acoustic waves. copyright American Geophysical Union 1988

• Research Organization: Amparo Corporation, Santa Fe, New Mexico
• OSTI ID: 5292852
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A1; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALTITUDE
DISTURBANCES
DOPPLER EFFECT
E REGION
EARTH ATMOSPHERE
EARTHQUAKES
ELECTROMAGNETIC RADIATION
IONOSPHERE
IONOSPHERIC STORMS
PLANETARY IONOSPHERES
PLASMA WAVES
RADIATIONS
RADIOWAVE RADIATION
SEISMIC EVENTS
SOUND WAVES
SUDDEN IONOSPHERIC DISTURBANCE
WAVE PROPAGATION