The TEC (Total Electron Content) of several GPS stations is derived with a resolution of 1°x1°x1h in the region of the Adriatic Sea. It was chosen because of the shallow earthquakes and the neighbourhood of the SEGMA stations. The regional densification is compared to the global TEC map by IGS (2.5°x2.5°x2h). The behaviour of the TEC maps around past, present and future earthquakes is investigated and compared to ‘quiet’ days. Daily and Seasonal and Sun activity effects must be considered before too.

 

In 2008 and 2009 two major earthquakes with Mw>5 happened in that region. In 2008 near Patras and 2009 at L'Aquila the TEC around the events have been investigated. Because no earthquake-related signals could be found the first conclusion is that those signals must be lower than 1 TECU. At both epicentres GPS stations are nearby (3-15 km) where the surface offsets are clearly seen at the cm level.