Possible seismo-ionosphere perturbations revealed by VLF signals collected on ground and on a satellite

• Published in: Natural Hazards and Earth System Sciences
• Main Authors: Rozhnoi, A., Molchanov, O., Solovieva, M., Gladyshev, V., Akentieva, O., Berthelier, Jean-Jacques, Parrot, Michel, Lefeuvre, François, Hayakawa, M., Castellana, L., Biagi, P. F.
• Other Authors: Schmidt United Institute of Physics of the Earth Moscow (IPE), Russian Academy of Sciences Moscow (RAS), Space Research Institute of the Russian Academy of Sciences (IKI), Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of Electro-Communications Tokyo (UEC), Department of Physics Bari, Università degli studi di Bari Aldo Moro = University of Bari Aldo Moro (UNIBA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Petropavlovsk; Kamchatka
• Online Access: https://hal.science/hal-00330926; https://hal.science/hal-00330926/document; https://hal.science/hal-00330926/file/nhess-7-617-2007.pdf; https://doi.org/10.5194/nhess-7-617-2007

International audience The results of the monitoring of three VLF/LF signals collected in Petropavlovsk station (Kamchatka, Russia) and one VLF signal collected on board of the DEMETER French satellite are presented. Two periods of the seismic activity occurred in the Japan-Kamchatka area during November–December 2004 and July–September 2005 were investigated and the earthquakes with M=6.0 in the Japan-Kamchatka area, located inside one or more of the third Fresnel zones of the three radio paths were considered. The ground data were analysed using residual signal of phase dP or of amplitude dA , defined as the difference between the signal and the average of few quiet days (±5 days) immediately preceding or following the current day. Also the satellite data were processed by a method based on the difference between the real signal and the reference one, but in order to obtain this last signal it was necessary to construct previously a model of the signal distribution over the selected area. The method consists: (a) in averaging all the data available in the considered region over a period characterized by low level seismicity, regardless of the global disturbances, in particular, of the magnetic activity; (b) in computing a polynomial expression for the surface as a function of the longitude and the latitude. The model well describes the real data in condition of their completeness and in absence of magnetic storms or seismic forcing. In the quoted periods of seismic activity clear anomalies both in the ground and in satellite data were revealed. The influence of the geomagnetic activity cannot to be excluded, but the seismic forcing seems more probable.