Bollettino Sismico Italiano 2012

Abstract

The Italian National Seismic Network (RSNI) in 2012 is described together with the seismicity occurred in Italy. In this year the RSNI has 413 seismic stations, belonging INGV and other local and regional networks, a part of which provides the signal in real time to the National Earthquake Center (CNT) in Rome. The Italian Seismic Bulletin (BSI) 2012 contains 18221 located earthquakes; a significant portion of this seismic activity belongs to the largest Emilian seismic sequence which mainly affected the provinces of Modena, Ferrara, Reggio Emilia, Bologna, Mantua and Rovigo, causing casualties, hundreds injured and serious damage to the artistic heritage, to rural and industrial construction, as well as to private homes (Fig. 1). On May 20 at 02:03 UTC an earthquake of ML 5.9 (5.8 MW) began the seismic sequence, preceded a few hours earlier by a 4.1 ML. On May 29, at 07:00 UTC, another strong earthquake (ML 5.8, 5.6 MW) struck the western sector of the area affected by the earthquake sequence. In 2012 the Emilian seismic sequence counted about 3100 earthquakes. In addition to the Emilia, we identified in 2012 other 27 seismic sequences. Among them, the sequence that affected the Pollino area is of particular interest; already started in 2009, continued throughout 2012: the strongest event occurred on October 25th, a magnitude 5.0 ML (5.2 MW) earthquake. The minimum magnitude of completeness of the BSI in 2012 is 1.4 MC. We have identified, in the seismicity of 2012, two new areas subject to anthropogenic activities, mostly quarry explosions. The BSI 2012 contains about 350 events of this type. We also analyze recordings produced by a collapse landslide, a phenomenon related to erosion widespread in our country, especially in the Alps.