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Space Research Institute, Graz, Austria 

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Space Research Institute, Graz, Austria 

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  1. Seismo-magnetic studies using the South European Geomagnetic Array (SEGMA)in the frame of the DEMETER projekt.K. Schwingenschuh(1), G. Prattes(2), M. Vellante(6), W. Magnes(1), M.Y. Boudjada(1), H. Biernat(1), J.J. Berthelier(3), E. Cristea(1), P. Pesec(1), P. Nenovski(4), M. Horn(5), M. Stachel(1).(1) Space Research Institute, Austrian Academy of Science, Graz, Austria (2) University of Technology, Graz, Austria (3) Centre d'Etude des Environnements Terrestre et Planétaires, Observatoire de Saint-Maur,France (4) Geophysical Institute, Sofia, Bulgaria (5) Institute of Physics, Department of Theoretical Physics, KF University Graz, Austria (6) Department of Physics, University of L’Aquila, Italy. Space Research Institute, Graz, Austria  Workshop on ‘Earthquakes: Ground-based and Space Observations‘ 1-2 June 2007

  2. Introduction • SEGMA founded in 2002 • Investigation of geomagnetic activity • 2004: begin of joint SEGMA-DEMETER studies • Ground-based magnetic field measurement up to 64 Hz • Method proposed by Hayakawa and Molchanov

  3. SEGMA stations

  4. Electromagnetic waves produced by microfractures • Physical model of seismomagnetic ULF- fluctuations by O. Molchanov and M. Hayakawa (1996). • Electromagnetic waves produced by microfractures. • Fracture size: 10-4m – 10-1m • Time scale: 10-4s – 10-7s • Velocity of opening: 103m/s. • Wideband electromagnetic noise • Damping of broadband electromagnetic waves, cutoff frequency ~1Hz.

  5. Seismomagnetic observations by Hayakawa 1996 • Guam earthquake 1993, Ms = 7.1. • Three ULF bands: • 10 – 50mHz, 50 – 100mHz, 100 – 450mHz. • Key parameter: • Ratio of vertical and horizontal field component (polarization). • Typical seismomagnetic amplitudes in the 10 – 50mHz band: • 0.1nT(Z- comp.) • Typical polarization ratio (Z/H): 1.5.

  6. Typical geomagnetic pulsations • Exampels: • PC3 pulsations/20.7.05 • x-component: • Time 08:32 – 08:35 • Max: 0.8nT • Period: 16s • y-component: • Time 08:32 – 08:35 • Max: 0.5nT • Period: 16s

  7. Typical geomagnetic pulsations cont PC4 pulsations/17.7.05 x-component: Time 22:40 – 22:55 Max: 1.5nT Period: 90s y-component: Time 22:40 – 22:55 Max: 2nT Period: 90s

  8. Skin depth and cutoff frequency of seismo-magnetic ULF waves μ0 …magnetic permeability σ... conductivity f … frequency Typical parameters: conductivity = 0.001 S/m skin depth = 10 km frequency f =2.5 Hz

  9. Future outlook • Measure the seismo-megnetic amplitude on the surface • Solve the inverse problem • Forecast parameter: magnitude, depth, conductivity profile, distance... • Combine SEGMA and DEMETER ULF/ELF observations • Planetary seismo-electromagnetic studies: Lunar orbiter and/or lander ?

  10. Publication list Nenovski, P. and Vellante, M, Compressional wave influence on the field-line resonance polarization, Compt.rend.Acad.bulg. Sci., 56, No 3, 21-26, 2003. Nenovski, P. and Boytchev, B., On the seismic source mechanism of electric signals, Aerospace Res. In Bulgaria, 17, 54-67, 2003. Nenovski, P., Boytchev, B., On the discharge mechanism of seismic electric signals, in Proc. Magnetic, Electric and Electromagnetic methods in Seismology and Vulcanology (MEEMSV), ed. V. Spichak, Troitsk, pp. 141-143, 2002. Nenovski, P., Komarov, L., and Andonov, B, Boundary effects on ULF wave field, Bulg. Geophys. J., 26, No 1-4, 144-153, 2000. Vellante, M., H. Luehr, T.L. Zhang, V. Wesztergom, U. Villante, M. De Lauretis, A. Piancatelli, M. Rother, K. Schwingenschuh, W. Koren, W. Magnes: ULF wave magnetic measurements by CHAMP satellite and SEGMA ground magnetometer array: case study of July 6, 2002, in Proceedings of the second CHAMP Science Meeting, Potsdam, Sept. 2003, Springer-Verlag, in press. Vellante, M., H. Luehr, T.L. Zhang, V. Wesztergom, U. Villante, M. De Lauretis, A. Piancatelli, M. Rother, K. Schwingenschuh, W. Koren, W. Magnes: Ground/satellite signatures of field line resonance: a test of theoretical predictions, J. Geophys. Res., in press. Vellante M., M. De Lauretis, U. Villante, N. Adorante, A. Piancatelli, K. Schwingenschuh, W. Magnes, W. Koren, and T.L. Zhang: A new meridional magnetometer array in middle-south Europe for monitoring dynamic processes in the coupled system plasmasphere-ionosphere, ESA SP, 477, 487-490, 2002. Villante U., M. Vellante, A. Piancatelli: Ultra low frequency geomagnetic field measurements during earthquake activity in Italy (September-October 1997), Annali di Geofisica, 44, 229-237, 2001. Pilipenko, V., Nenovski, P. and Tanaka, H., Detection and discrimination of VLF/ULF seismic-related electromagnetic emissions, Bulg. Geophys. J., XXIX, in press Villante U., M. Vellante, A. Piancatelli, A. Di Cienzo, T.L. Zhang, W. Magnes, V. Wesztergom, A. Meloni: Some aspects of man made conatmination on ULF measurements. G. Prattes, K. Schwingenschuh, W. Magnes, M. Boudjada, M. Horn, M. Vellante: Investigation of electromagnetic ULF/ELF-phenomena possibly related to the july 10th 2005 Podgorica seismic event using South European Ground Magnetometer (SEGMA) and DEMETER data.

  11. SEGMA stations cont. Magnetic field data is measured at the following locations signed with yellow markers in the map.

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