Articles | Volume 11, issue 6
https://doi.org/10.5194/nhess-11-1807-2011
https://doi.org/10.5194/nhess-11-1807-2011
Research article
 | 
28 Jun 2011
Research article |  | 28 Jun 2011

Daytime variations of foE connected to earthquakes

E. V. Liperovskaya, V. V. Bogdanov, P.-F. Biagi, C.-V. Meister, and V. A. Liperovsky

Abstract. In the present work it is shown that, in accordance with the observations of the vertical sounding station "Tashkent", the critical foE-frequency of the daytime E-layer increases about one day before winter-earthquakes with magnitudes M > 5 and depths of the epicentre of h < 60 km, which appeared at distances of R < 2000 km from the station. The reliability of the result is larger than 99 %. The phenomenon is not observed for summer-earthquakes. It seems to be determined by the atmospheric wind system. Further, the variations of the foE-frequency are compared with possible simultaneous variations of the critical frequency foF2 of the F2-layer. First results show that only very large changes of the ionisation density in the E-layer influence the ionisation density in the F-region. Therefore, no synchronous growth of the foE- and foF2-frequencies 1–2 days before seismic shocks could be observed.

Download
Altmetrics