Seismicity and focal mechanisms at the Calabro-Lucanian boundary along the Apennine Chain (Southern Italy)

Abstract

The Calabro-Lucanian boundary is a complex geological zone marking the transition between the highly seismogenic tectonic domains of Southern Apennines and the Calabrian Arc. Historical catalogues include earthquakes with macroseismic effects up to VII-VIII MCS (CPTI WORKING GROUP, 2004) and paleoseismological investigations suggested that earthquakes of magnitude between 6.5 and 7 may have occurred in this area, between the 6th and the 15th century (MICHETTI et alii, 2000). More recently, on 9 September 1998, an earthquake of moment magnitude M5.6 occurred at the north-western margin of the Pollino massif (GUERRA et alii, 2005; ARRIGO et alii, 2006) and since the second half of 2010 the same region was interested by a noteworthy seismic activity characterized by several swarms with thousands of events with a maximum magnitude of 3.6.