GNGTS 2013 - Atti del 32° Convegno Nazionale

Fig. 1 - A) Seismic activity in the Pollino region (events with depths less than 50 km and located in a radius of 100 km from Mormanno in the period 2010-2012). The top panel shows the number of daily events. In the lower panel is the logarithm of the cumulative seismic moment (calculated following Kanamori, 1977). The coloured bars show the three major earthquake swarms and the vertical red lines indicate the time of occurrence of the most energetic event of each cluster. B) Relative seismic velocity variations (percentage) obtained by the analysis of the ambient seismic noise cross-correlations of the 18 stations considered (153 pairs of stations) in the Pollino region. Each point together with its error bar represent the result obtained for the 50 previous days. The colour scale indicates the number of pairs involved in estimating every single measurement: warm colours are for values obtained on a large number of station pairs and correspond to more stable results. C) Relative velocity variations (percentage) obtained from the analysis of the ambient seismic noise cross-correlations for the 9 stations considered in the Po plain. Each point together with its error bar represent the result obtained for the 50 previous days. The colour scale indicates the number of pairs involved in estimating every single measurement: warm colours are for values obtained on a large number of station pairs and correspond to more stable results. The vertical red line marks the beginning of the Emilia sequence. 111 GNGTS 2013 S essione 2.1