Ionospheric variations associated with November 28, 2004 Japanese earthquake

In this paper we present the analysis of the ionosphere changes prior to the Japanese earthquake of November 28, 2004 (M7.0). For this purpose we used global TEC maps and measurements provided by GPS-IGS stations and Wakkanai ionosonde which is nearest to the epicenter. Several days prior to earthquake the characteristic anomaly was found out as the day-time significant increase of TEC at the vicinity of earthquake up to the value of 45-48% relative to the background condition.