Pattern of seismicity in the Lucanian Apennines and foredeep (Southern Italy) from recording by SAPTEX temporary array

• Main Authors: P. De Gori, G. B. Cimini, L. Amicucci, F. R. Cinti, A. Frepoli, S. Pierdominici
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 2005-06-01
• Series: Annals of Geophysics
• Subjects: seismicity; seismic network; motectonics; Lucanian Apennines; Lucanian foredeep; Southern Italy
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/3252

The deployment of a temporary seismic network in Southern Italy during 2001-2004 (the SAPTEX array, Southern
 APennine Tomography EXperiment) allowed us to relocate the hypocenters of Southern Apennines earthquakes
 with low uncertainty among the location parameters. The best array distribution of the SAPTEX network
 for the analysis of seismicity in the Lucanian Apennines and foredeep was reached in the first two years of
 recording. The SAPTEX data were merged with those of the Italian National Seismic Network (RSNC) operated
 by the Istituto Nazionale di Geofisica e Vulcanologia (INGV). For the hypocenters computation of events in
 the upper Agri Valley we also included P- and S- waves arrivals from the local Eni-Agip network. The seismicity
 for the Lucanian Apennines and foredeep in the analyzed period has magnitudes ranging from 2.0 to 4.1. A
 major finding is the identification of two different crustal domains: the westernmost characterizing the chain,
 mostly with shallow earthquakes (within about 20 km of depth), and the easternmost one belonging to the outer
 margin of the chain and to the foredeep, with deeper seismicity (mostly between 20-40 km of depth). Thirty
 fault-plane solutions were computed and used for stress inversion; most of them are related to earthquakes within
 the chain sector and indicate a generalized NE-SW extension. Moreover, the dense network allowed us to improve
 the location of events relative to two low magnitude sequences which occurred in the study period.