GNGTS 2014 - Atti del 33° Convegno Nazionale

96 GNGTS 2014 S essione 2.1 for all the TIR SEVIRI/MSG images in between January 2012 and present for the testing area of Po Plain and the analysis performed following the new objectives of the Project for its 2 nd year of activities. In this case, in fact, the full range of RETIRA values (as they represents the weighted residuals of TIR signal after the removal of contribution coming from daily/annual solar cycle and some meteorological forcing) were investigated at a wider space-time scale. Fig. 2 shows, for instance, some of the preliminary results achieved in the case of Emilia earthquakes (May 20, 2012, M=5,9 and May 29, M=5,8) for which previous analyses showed the occurrence of TIR anomalies of lower intensity (2<RETIRA<3) on May 13 without the characteristic of space-time persistence (but clouds were also frequently present over that area) required to consider it significant (see before) in the framework of the a traditional search for possible pre-seismic anomalies. The new analysis, however, better emphasize not only the growing of the area affected by the 2σ anomaly around the epicentre area since May 13 and before, but allows to identify patterns of growing values of RETIRA with quite evident spatial relationship with main fault system in the northern Apennine area. Fig. 2 – Distribution of RETIRA values in the day before the Emilia earthquakes of May 20 and 29, 2012 (see text).