GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 1.1 75 analysis is shown in Fig. 2 in the case of the the Visso MW 5.9 earthquake. The solid line in Fig. 2 represents the theoretical back azimuth. We can see that for this event the surface Love waves are very clear also in the seismogram and that, at periods longer than 3 seconds, the BAZ estimation is in good accord with the theoretical one. In the band represented by a central frequency of 2 Hz we can see that this method is very effective in identifying a region of high coherence corresponding to what we identify as the SH arrival with the correct BAZ. The analysis shown in Fig. 2 basically allow us to understand from where the different frequencies are coming from in the different seismic phases, we remark that this kind of analysis is only possible by exploiting seismometer array measures. We also remark that this method is Tab. 1 - Parameters of the main events of the sequence. Start Time Mag Dist [km] BAZ [deg] Depth [km] Event N. 26-Oct-2016 19:18:05 5.9 62.3 324.6 7.5 1 26-Oct-2016 17:10:35 5.4 59.8 322.6 8.7 2 01-Nov-2016 07:56:36 4.8 69.5 331.0 9.9 3 03-Nov-2016 00:35:00 4.7 77.0 326.4 8.4 4 30-Oct-2016 13:34:54 4.5 51.2 319.5 9.2 5 30-Oct-2016 12:06:59 4.5 59.4 317.2 9.7 6 26-Oct-2016 21:41:59 4.5 58.1 321.4 9.9 7 27-Oct-2016 08:21:45 4.3 60.6 320.5 9.4 8 31-Oct-2016 07:05:44 4.2 56.4 320.1 10.0 9 30-Oct-2016 10:19:25 4.1 53.3 319.1 10.8 10 27-Oct-2016 03:19:26 4.0 55.5 321.6 9.2 11 16-Oct-2016 09:32:34 4.0 46.1 315.4 9.2 12 31-Oct-2016 06:17:19 3.9 46.3 319.9 9.9 13 27-Oct-2016 17:22:22 3.9 57.9 319.1 9.0 14 08-Oct-2016 18:11:08 3.9 44.8 315.1 9.5 15 07-Nov-2016 18:56:15 3.8 59.4 324.6 8.1 16 28-Oct-2016 15:56:58 3.8 52.6 315.2 9.8 17 26-Oct-2016 19:43:42 3.8 63.9 320.1 12.6 18 09-Nov-2016 06:13:09 3.7 38.8 306.7 10.7 19 30-Oct-2016 12:32:56 3.7 39.7 317.3 8.2 20 30-Oct-2016 11:14:20 3.7 49.9 321.3 9.4 21 28-Oct-2016 19:56:31 3.7 56.9 323.9 13.2 22 26-Oct-2016 21:24:51 3.7 61.3 318.8 10.3 23 06-Nov-2016 18:15:17 3.6 50.5 321.2 8.9 24 05-Nov-2016 08:17:39 3.6 44.3 308.2 11.1 25 31-Oct-2016 09:34:16 3.6 53.1 319.6 9.2 26 30-Oct-2016 23:56:19 3.6 57.4 316.7 7.9 27 30-Oct-2016 10:26:24 3.6 59.1 316.2 10.8 28 09-Oct-2016 04:42:42 3.6 45.0 315.3 11.8 29 02-Nov-2016 06:41:12 3.5 50.6 319.1 10.3 30 01-Nov-2016 17:59:12 3.5 53.1 317.8 10.8 31 30-Oct-2016 13:14:16 3.5 54.4 309.9 8.7 32 28-Oct-2016 23:18:08 3.5 61.5 320.6 14.0 33