Post-seismic Ionosphere Effects after Croatian MW 6.4 Earthquake on December 29, 2020

Abstract

The main idea of the present investigation is to study the relationship between post- seismic effects as a result of Petrinja, Croatia earthquake which occurred on December 29, 2020 in some ionospheric parameters. Two types of ionospheric data were used: the critical frequency of the F2 region (foF2), obtained from the vertical sounding of the ionosphere and Total Electron Content (TEC) data. The ionospheric response is studied by the relative deviation of both quantities foF2 and TEC. The results of the ionospheric parameter behaviour show the following: a) a positive anomaly is observed in both ionospheric characteristics; b) the most significant positive response is observed at ionospheric stations closer to the epicentre; c) the delay of the observed post-seismic ionospheric effect increases with distance from the epicentre in both data used. The observed anomalies in the behaviour of considered ionospheric parameters could be associated with the considered lithospheric phenomenon because the selected period is with completely quiet geomagnetic conditions. The results of this research gives additional insight into the Lithosphere-Atmosphere-Ionosphere Coupling during Earthquake processes.