Possible detection of ionospheric disturbances during the Sumatra-Andaman islands earthquakes of December, 2004

Abstract

The results of the continuous monitoring of ionospheric disturbances using very low frequency (VLF) radio waves during the recent Sumatran earthquake are presented. Strong and anomalous shifts in the sunset-terminator are found during 22-31 Dec. 2004. Anomalous behaviours in daytime observation are also detected. On 26 Dec. 2004, there were altogether

23 major earthquakes and aftershocks (magnitudes 5.0-9.0 on Richter scale). There were JO such earthquakes on 27 Dec., 2 on 28 Dec., 7 on 29 Dec. and 4 on the 30 Dec. 2004. Given that there was no major earthquake on 22 December, though anomaly began on that day, it is believed that VLF monitoring could be a useful tool for earthquake predictions as well.