| Abstract: | Some anomalies are observed in the subinospheric VLF electromagnetic (EM) signals at 19.8 kHz transmitted from North West
Cape, Australia (lat: 21.82° S; long: 114.16° E) and 40 kHz from Fukushima, Japan (lat: 36.18° N, long: 139.85° E), recorded
by VLF receivers near Kolkata (lat: 22.56° N, long: 88.5° E) during the occurrence of the two earthquakes at Andaman Island
(lat:14.018° N, long: 92.92° E), India and other at South Coast of Honsu (lat: 34.78° N, long: 138.27° E), Japan. The analyses
of these seismo-ionospheric VLF EM anomalies at these two frequencies during some days before and after the occurrence of
earthquake on August 11, 2009 will be presented here. VLF-LF transient variations of significant magnitude in the form of
spikes are observed few days prior to the day of occurrence of the earthquakes that continued several days more, then decaying
gradually and finally ceased. Signals are examined to describe their connectivity with earthquakes. The enhancements of the
amplitude and frequency of the fourth mode of Schumann resonance spectra have been detected during the occurrence of the two
earthquakes, which will also be reported here. |
