Atmospheric anomalies observed during earthquake occurrences
Article first published online: 11 SEP 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 17, September 2004
How to Cite
2004), Atmospheric anomalies observed during earthquake occurrences, Geophys. Res. Lett., 31, L17110, doi:10.1029/2004GL019865., , , , , , , , , and (
- Issue published online: 11 SEP 2004
- Article first published online: 11 SEP 2004
- Manuscript Accepted: 4 AUG 2004
- Manuscript Revised: 26 JUL 2004
- Manuscript Received: 2 MAR 2004
 Appearance of anomalies in the atmosphere before earthquakes (EQs) has been verified, through observation of anomalous transmission of VHF electromagnetic (EM) waves beyond line-of-sight. Anomalous increase of the received intensity for a few minutes - several hours on a day was identified by the previous 15-day running median and its inter-quartile range. The cross-correlation between the EQ occurrences and the anomalies shows that the appearance of anomalies was significantly enhanced within 5 days before M ≥ 4.8 EQs. The one-day average number of the anomaly appearance within 5 days was found 2.4 times larger than that of other days. Through the polarization measurement of the received EM waves, the anomalies were found to occur in the atmosphere.