Articles | Volume 6, issue 5
Nat. Hazards Earth Syst. Sci., 6, 741–744, 2006

Special issue: Seismo-tectonic electromagnetic effects, precursory phenomena...

Nat. Hazards Earth Syst. Sci., 6, 741–744, 2006

  22 Aug 2006

22 Aug 2006

On Es-spread effects in the ionosphere connected to earthquakes

E. V. Liperovskaya1, C.-V. Meister2, O. A. Pokhotelov1, M. Parrot3, V. V. Bogdanov4, and N. E. Vasil'eva1 E. V. Liperovskaya et al.
  • 1Institute for Physics of the Earth, 123995 Moscow, Russia
  • 2High School and Science Programme Brandenburg/Potsdam, Project "Physics of Stellar and Planetary Atmospheres", 14482 Potsdam, Germany
  • 3L.P.C.E./C.N.R.S., 3A, Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France
  • 4Inst. of Cosmophysical Research and Radio Wave Propagation, Far Eastern Branch of RAS, 684034 P-Kamchatsky, Russia

Abstract. In the present work, phenomena in the ionosphere are studied, which are connected with earthquakes (16 events) having a depth of less than 50 km and a magnitude M larger than 4. Analysed are night-time Es-spread effects using data of the vertical sounding station Petropavlovsk-Kamchatsky (φ=53.0°, λ=158.7°) from May 2004 until August 2004 registered every 15 min. It is found that the maximum distance of the earthquake from the sounding station, where pre-seismic phenomena are yet observable, depends on the magnitude of the earthquake. Further it is shown that 1–2 days before the earthquakes, in the pre-midnight hours, the appearance of Es-spread increases. With a probability of more than 0.95, this increase of Es-spread observations before midnight is not casual.