Decrease of VLF transmitter signal and Chorus-whistler waves before l'Aquila earthquake occurrence

M. Y. Boudjada (1) , K. Schwingenschuh (1) , R. Döller (2) , A. Rohznoi (3) , Michel Parrot (4) , P. F. Biagi (5) , Patrick H. M. Galopeau (6) , M. Solovieva (3) , O. Molchanov (3) , H.K. Biernat (1, 7) , G. Stangl (8) , H. Lammer (1) , I. Moldovan (9) , W. Voller (1) , M. Ampferer (2)

1 IWF - Space Research Institute of Austrian Academy of Sciences
2 IGAM - Institute for Geophysics, Astrophysics and Meteorology [Graz]
3 IPE - Schmidt United Institute of Physics of the Earth [Moscow]
4 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
5 Department of Physics [Bari]
6 HELIOS - LATMOS
7 Department of Theoretical Physics [Graz]
8 BEV - Federal Office of Metrology and Surveying [Vienna]
9 NIEP - National Institute for Earth Physics [Romania] - Institutul Național pentru Fizica Pământului

We investigate the VLF emissions observed by the Instrument Champ Electrique (ICE) experiment onboard the DEMETER micro-satellite. We analyze intensity level variation 10 days before and after the occurrence of l'Aquila earthquake (EQ). We found a clear decrease of the VLF received signal related to ionospheric whistler mode (mainly Chorus emission) and to signal transmitted by the DFY VLF station in Germany, few days (more than one week) before the earthquake. The VLF power spectral density decreases of more than two orders of magnitude until the EQ, and it recovers to normal levels just after the EQ occurrence. The ge-omagnetic activity is principally weak four days before EQ and increases again one day before l'Aquila seismic event. Our results are discussed in the frame of short-and long-terms earthquakes prediction focusing on the crucial role of the magnetic field of the Earth.

Domaines: Planète et Univers [physics]; Physique Atmosphérique et Océanique [physics.ao-ph]

M. Y. Boudjada, K. Schwingenschuh, R. Döller, A. Rohznoi, Michel Parrot, et al.. Decrease of VLF transmitter signal and Chorus-whistler waves before l'Aquila earthquake occurrence. Natural Hazards and Earth System Sciences, 2010, 10, pp.1487-1494. ⟨10.5194/nhess-10-1487-2010⟩. ⟨insu-01180562⟩