The Ongoing Seismic Sequence at the Pollino Mountains, Italy

Abstract

A sequence of thousands of small to moderate earthquakes has been occurring since spring 2010 in the Pollino Mountains area, southern Italy (Fig. 1), where a seismic gap was previously hypothesized by paleoseismological evidence associated with the lack of major earthquakes in historical catalogs (Michetti et al. , 2000; Cinti et al. , 2002). Seismic activity is in progress at the time of writing of this paper (December 2012) after quite a disturbing long‐term acceleration of earthquake rate and strain release (Fig. 1b). The strongest earthquake ( M L 5.0 according to the Italian Seismological Instrumental and parametric Data‐basE [ISIDE], http://iside.rm.ingv.it; last accessed September 2013) was recorded on 25 October 2012 and produced damage in the epicentral area corresponding to a maximum intensity of 6 on the European Macroseismic Scale 1998 (EMS‐98) in the localities of Mormanno, Campotenese, and Piano Incoronata (Fig. 2; D’Amico and Scarfi, 2012). Because of this earthquake, more than a thousand people were evacuated from their homes and emergency actions have been carried out by the competent institutions. This earthquake with its effects, and the increasing number and intensity of events felt by the population in the preceding months, have further encouraged the attention and efforts of civil defense operators and scientific researchers toward this peculiar seismic crisis occurring in a presumed seismic‐gap area. It should also be remarked that the Pollino area, lying at the northern edge of the Calabrian subduction zone (Fig. 1a), represents a highly deformed, very intricate sector of great geodynamic interest and still not fully understood (see, e.g., Bonini et al. , 2011; Frepoli et al. , 2011; Spina et al. , 2011; Neri et al. , 2012). The present study, which focuses on the ongoing Pollino …