GNGTS 2018 - 37° Convegno Nazionale

760 GNGTS 2018 S essione 3.3 as Long Period events, volcanic tremor, tectonic earthquakes and/or fluid-induced seismicity buried in noisy environments. Moreover, the ICAP provides fast decomposition into simpler wave-packets corresponding to the main seismic phases. The ICAP, compared to standard techniques, is suitable to retrieve polarization parameters in a “single step” using the whole waveforms, avoiding a-priori segmentation and/or filtering of the signals. Real time implementation of ICA/ICAP in monitoring networks for the analysis of the seismic signals would reduce repetitive and painstaking work performed by the analysts, thus improving the surveillance levels of high-risk volcanic and tectonic areas. Fig. 3 - Comparison between the particle motion of the raw data and the ICs, for the Amatrice earthquake occurred on 2016, August 24 th . On the left, the hodograms (EW-NS) of the raw signal (blue line) calculated in two time windows containing the P and S-phase, respectively, and of the two ICs (red and green lines). The corresponding azimuth values obtained for the ICs are 163° for the P- and 7° for the S-phase, in agreement with those inferred from the standard polarization analysis (covariance matrix technique) shown in the right panel. Fig. 2 - Comparison between the particle motion of the raw data and the ICs, for the VT earthquake recorded at Campi Flegrei on 2015, October 7 th . In each row of the figure, the hodograms (EW-NS, NS-Z, EW-Z) of the raw signal (blue line) are calculated in two time windows (TW1 and TW2) containing the P and S-phase, respectively. The trajectory of the ICs is represented in red and green.