Prattes G

Publications (2)0 Total impact

• Source

  Available from: Umberto Villante

  Article: The 6 April 2009 earthquake at L'Aquila: a preliminary analysis of magnetic field measurements

  Villante U, M. De Lauretis, C. De Paulis, Francia P, Piancatelli A, Pietropaolo E, Vellante M, Meloni A, Palangio P, Schwingenschuh K, Prattes G, Magnes W, Nenovski P
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  ABSTRACT: Several investigations reported the possible identification of anomalous geomagnetic field signals prior to earthquake occurrence. In the ULF frequency range, candidates for precursory signatures have been proposed in the increase in the noise background and polarization parameter (i.e. the ratio between the amplitude/power of the vertical component and that one of the horizontal component), in the changing characteristics of the slope of the power spectrum and fractal dimension, in the possible occurrence of short duration pulses. We conducted, with conventional techniques of data processing, a preliminary analysis of the magnetic field observations performed at L'Aquila during three months preceding the 6 April 2009 earthquake, focusing attention on the possible occurrence of features similar to those identified in previous events. Within the limits of this analysis, we do not find compelling evidence for any of the features which have been proposed as earthquake precursors: indeed, most of aspects of our observations (which, in some cases, appear consistent with previous findings) might be interpreted in terms of the general magnetospheric conditions and/or of different sources.
  Natural Hazards and Earth System Sciences. 01/2010;
• Source

  Available from: nat-hazards-earth-syst-sci.net

  Article: Ionospheric conductivity effects on electrostatic field penetration into the ionosphere

  V. V. Denisenko, M. Y. Boudjada, Horn M, E. V. Pomozov, H. K. Biernat, Schwingenschuh K, Lammer H, Prattes G, Cristea E
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  ABSTRACT: The classic approach to calculate the electrostatic field penetration, from the Earth's surface into the ionosphere, is to consider the following equation ∇·(σ·∇Φ)=0 where σ and Φ are the electric conductivity and the potential of the electric field, respectively. The penetration characteristics strongly depend on the conductivities of atmosphere and ionosphere. To estimate the electrostatic field penetration up to the orbital height of DEMETER satellite (about 700 km) the role of the ionosphere must be analyzed. It is done with help of a special upper boundary condition for the atmospheric electric field. In this paper, we investigate the influence of the ionospheric conductivity on the electrostatic field penetration from the Earth's surface into the ionosphere. We show that the magnitude of the ionospheric electric field penetrated from the ground is inverse proportional to the value of the ionospheric Pedersen conductance. So its typical value in day-time is about hundred times less than in night-time.
  Natural Hazards and Earth System Sciences. 01/2008;