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Institute of Geophysics, Warszawa, Poland
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- PublicationOpen AccessCentral Italy magnetotelluric investigation. Structures and relations to seismic events: analysis of initial data(1996-01)
; ; ; ; ; ; ;Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Marchetti, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Teisseyre, E.; Institute of Geophysics, Warszawa, Poland ;Marianiuk, J.; Institute of Geophysics, Warszawa, Poland ;Ernst, T.; Institute of Geophysics, Warszawa, Poland; ; ; ; ; A scientific collaboration between the Warsaw Academy of Science, (Poland) and the National Institute of Geophysics (Italy), gave rise to the installation of few stations for the long term measurement of magnetotelluric fields in central Italy. The selection of investigation sites was determined by the individual seismic interest of each location. The project began in the summer of 1991, with the installation of 2 magnetotelluric stations in the province of Isernia, (Collemeluccio and Montedimezzo). In 1992, 2 more stations became operative, one in the province of Rieti, (Fassinoro), the other in the province of L'Aquila, (S. Vittoria). For the purpose of this project, the magnetic observatory in L'Aquila was also equipped with electric lines, for the measurement of the telluric field. The aim of the analysis here presented, is to show that is possible to follow the temporal evolution of magnetotelluric characteristic parameters. At Collemeluccio this evolution was compared with the seismic released energy for events recorded within the study area.269 264 - PublicationOpen AccessMagnetic variation analysis for the June 1993 seismic events in Central Italy(1997-03)
; ; ; ; ; ;Ernst, T.; Institute of Geophysics, Warszawa, Poland ;Teisseyre, R.; Institute of Geophysics, Warszawa, Poland ;Meloni, A.; Istituto Nazionale di Geofisica, Roma, Italy ;Palangio, P.; Istituto Nazionale di Geofisica, Roma, Italy ;Marchetti, M.; Istituto Nazionale di Geofisica, Roma, Italy; ; ; ; A scientific collaboration between the Istituto Nazionale di Geofisica (Italy) and the Warsaw Academy of Science (Poland) gave rise to the installation of a few stations for the long-term measurement of magnetotelluric fields in Central Italy. The investigation sites were determined following the individual seismic interest of each location. For this project, the magnetic observatory in L'Aquila was also equipped with electric lines, for simultaneous measurements of the telluric field. After a few years of experience some of the installed stations had to be removed for their high noise level that made this study almost impossible. A first time interval was considered from January 1992 to February 1993 and showed the existence of significant changes in magnetotelluric parameters related to earthquake occurrence time, an extension of that analysis was made to include the event of June 1993 using the magnetic field time variation.173 120 - PublicationOpen AccessElectromagnetic radiation related to dislocation dynamics in a seismic preparation zone(2002)
; ; ;Teisseyre, R.; Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland ;Ernst, T.; Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland; Electromagnetic emission is observed frequently before earthquakes as high noise level in VLF and ULF bands. We present theoretical considerations on electromagnetic radiation caused by dislocation dynamics in the preseismic micro-sources (micro-crackings) located in an earthquake preparation zone. Some of these micro-sources could be located near the ground surface and their electromagnetic signals could be accesible in some recording stations. The examples of the numerically simulated induction and radiation fields are given and one example of the observed radio-noise recording is shown.148 219 - PublicationRestrictedObservations of Electromagnetic Radiation in the Central Apennines Seismic Region(2001)
; ; ; ; ; ;Ernst, T.; Institute of Geophysics, Polish Academy of Sciences, ul. Ksiecia Janusza 64, 01-452 Warszawa, Poland ;Jankowski, J.; Institute of Geophysics, Polish Academy of Sciences, ul. Ksiecia Janusza 64, 01-452 Warszawa, Poland ;Teisseyre, R.; Institute of Geophysics, Polish Academy of Sciences, ul. Ksiecia Janusza 64, 01-452 Warszawa, Poland ;Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; In recent years, continuous radio-noise recording is in use at many geophysical observatories, in order to detect possible earthquake precursors and/or coseismic signals. The recordings obtained indicate that electromagnetic radiation (e.g., in the range of 10-40 kH) can indeed be treated as seismic precursor. We present here the examples of successful prediction observation, which we have obtained in the Central Apennines region at the l'Aquila Observatory (Polish-Italian cooperation). A short discussion on relation between the evolution of stresses (dislocation dynamics) and electromagnetic emission supplements this paper.249 78 - PublicationOpen AccessEvolution of magnetotelluric, total magnetic field, and VLF field parameters in Central Italy: relations to local seismic activity(2001-04)
; ; ; ; ; ; ;Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Di Mauro, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Mele, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Ernst, T.; Institute of Geophysics, Warszawa, Poland ;Teisseyre, R.; Institute of Geophysics, Warszawa, Poland; ; ; ; ; Magnetotelluric data were collected at Collemeluccio (41.72°N, 14.37°E) in Central Italy from summer 1991 to spring 1998. Analyzed by means of tensor decomposition on the geoelectric potential and robust estimation on the geomagnetic field, this set of data allowed the investigation of the electric properties at different time-periods. The variation of some indicators, related to the phenomenon of electromagnetic induction, is presented here in its time evolution and compared to local and regional seismic activity. Tectonomagnetic field observations from absolute magnetic field level in Central Italy were also made on data simultaneously recorded at four magnetometer stations, using L'Aquila Geomagnetic Observatory as a reference for differentiation. Recent results gathered from a system of two VLF search coil wide-band antennas, installed in the L'Aquila Observatory, are also discussed in relation to local seismic activity.255 417