Preseismic Modification of the Ionosphere for Greece 2006 Earthquake : GPS TEC Measurements and Modeling Results Numerical Modeling
In this paper we present the specific features of TEC (total electron content of the ionosphere) behavior as possible precursors of Southern Greece earthquake of January 8, 2006 (M6.8). The ionosphere modification as the cloud like increase of electron concentration situated in the immediate vicinity from the forthcoming earthquake epicenter has been revealed 1 day prior to the main shock. The amplitude of modification reached the value of 50% relative to the non-disturbed condition and was in existence from 10 UT till 22 UT. The area of significant TEC enhancement had the sizes of about 4000 km in longitude and 1500 km in latitude. The model calculations of the ionosphere response to the action of zonal electric field produced by seismogenic sources located at the middle latitudes were done. The results of calculation were compared with observational data obtained.