GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 recent weeks (Figure 2B). Observatons shown in Figure 2 are intriguing, although we can not produce solid proof of the recent anomaly being a foretremor.  Figure 2. A) In red, the long term rate of non-volcanic tremor NVT (~8500 days) smoothed using a 10-day window (min/day); in black, the cumulatve tremor actvity (min). B) The detrended cumulatve tremor actvity. C) Rate of tremor 10-day smoothed (minutes/day) in the 293-day (9.7-month) 7-month tme windows: May 7, 2004 - February 24, 2005. D) Rate of tremor 10-day smoothed (minutes/day) in the tme window Jun 13, 2023 - April, 1, 2024. Bracketng dates of the two tme windows of C and D are indicated in A and B by vertcal dashed red lines. The behaviour of the atenuaton parameter during the latest porton of the earthquake cycle that ended with the mainshock of 28 September 2004 is shown in Figure 3, where are the logarithms of the ratos between spectral amplitudes taken at two specifc hypocentral distances of 12 and 4 km