GNGTS 2013 - Atti del 32° Convegno Nazionale

(http://www.distav.unige.it/geofisica/) using standard monitoring procedures. Approximately 2800 micro-earthquakes were subsequently identified using an automatic detection algorithm based on the STA/LTA (short-term average/long-term average) triggering method (e.g., Withers et al. , 1998; Sharma et al. , 2010). The Lunigiana sequence shocked an area comprised between the provinces of Lucca and Massa Carrara. The main shock, with local magnitude of 5.2, occurred near the municipalities of Minucciano (Lucca) and Casola in Lunigiana (Massa Carrara). More than 1800 aftershocks, with magnitude up to 4.4, were recorded by the RSNI network following the main shock. The analysis of such seismic episodes is performed both to study the causative sources and to investigate possible changes in the scaling exponent ( b -value) of the Gutenberg and Richter (1944) relationship within the rock volume involved during the events. Fig. 1 – Left panel: distribution of the instrumental seismicity ( Ml ≥ 2.0) recorded by the RSNI network in the area surrounding the Sampeyre swarm; the events belonging to the investigated seismic crisis are displayed by red points. Right panels: seismicity distribution (top panel) and longitudinal cross section of hypocenters (bottom panel) after double-difference location. Light- and dark-gray circles indicate the events belonging to Family 1 and Family 2, respectively. 18 GNGTS 2013 S essione 1.1