Articles | Volume 3, issue 3/4
Nat. Hazards Earth Syst. Sci., 3, 203–209, 2003
https://doi.org/10.5194/nhess-3-203-2003

Special issue: Earthquake Precursory Phenomena

Nat. Hazards Earth Syst. Sci., 3, 203–209, 2003
https://doi.org/10.5194/nhess-3-203-2003

  31 Aug 2003

31 Aug 2003

Preseismic ULF electromagnetic effect from observation at Kamchatka

O. Molchanov1, A. Schekotov1, E. Fedorov1, G. Belyaev1, and E. Gordeev2 O. Molchanov et al.
  • 1Institute of the Physics of the Earth, Moscow, Russia
  • 2Institute of Geophysical Survey, Petropavlovsk-Kamchatski, Russia

Abstract. Some results of ULF magnetic field observation at Karimshino site (Kamchatka, Russia) since June 2000 to September 2001 are presented here. Using case study we have found an effect of suppression of ULF intensity about 2–6 days before rather strong and nearby seismic shocks (magnitude M = 4.0 – 6.2). It is revealed for nighttime and horizontal component of ULF field (G) in the frequency range 0.01 – 0.1 Hz. Then we prove the reliability of the effect by computed correlation between G (or 1/G) and specially calculated seismic indexes Ks for the whole period of observation. Basing on the simple criteria we conclude that reliability of seismo-associated ULF suppression effect is comparable with well-known effect of connection between ULF variation and Kp index of global magnetic activity. It seems the reason of suppression is located at the atmosphere or ionosphere but not in the ground medium.

Download
Altmetrics