A statistical study on the effect of earthquakes on the ionosphere, based on the subionospheric LF propagation data in Japan

Abstract : A superimposed epoch analysis has been undertaken, in order to find the correlation of the ionospheric perturbations with seismic activity. We take the wave path from the Japanese LF transmitter (frequency=40 kHz) and an observing station of Kochi (wave path length of 770 km), and a much longer period (of five years) than before, is considered. This subionospheric LF propagation can be called "an integrated measurement" in the sense that any earthquakes in the LF sensitive area just around the great-circle path can influence the observed LF signals, so that we define the "effective magnitude" (Meff) by integrating the total energy from different earthquakes in the sensitive area on a current day and by converting it back into magnitude. A superimposed epoch analysis for the effective magnitude greater than 6.0 has yielded that the ionosphere is definitely disturbed in terms of both amplitude and dispersion, and that these perturbations tend to take place prior to an earthquake. The statistical z-test has also been performed, which has indicated that the amplitude is definitely depleted 2?6 days before the earthquake day and also that the dispersion is very much enhanced during the same period. This statistical study has given strong support to the existence of seismo-ionospheric perturbations for high seismic activity.
Type de document :
Article dans une revue
Annales Geophysicae, European Geosciences Union, 2006, 24 (8), pp.2219-2225
Liste complète des métadonnées

Littérature citée [32 références]  Voir  Masquer  Télécharger

https://hal.archives-ouvertes.fr/hal-00318154
Contributeur : Publication Egu <>
Soumis le : mercredi 13 septembre 2006 - 08:00:00
Dernière modification le : mercredi 3 septembre 2008 - 18:20:08
Document(s) archivé(s) le : jeudi 3 juin 2010 - 20:27:43

Fichier

angeo-24-2219-2006.pdf
Accord explicite pour ce dépôt

Identifiants

  • HAL Id : hal-00318154, version 1

Collections

INSU | EGU

Citation

S. Maekawa, T. Horie, T. Yamauchi, T. Sawaya, M. Ishikawa, et al.. A statistical study on the effect of earthquakes on the ionosphere, based on the subionospheric LF propagation data in Japan. Annales Geophysicae, European Geosciences Union, 2006, 24 (8), pp.2219-2225. 〈hal-00318154〉

Partager

Métriques

Consultations de la notice

302

Téléchargements de fichiers

223