Sources of Mw 5+ earthquakes in northeastern Italy and western Slovenia: an updated view based on geological and seismological evidence Pierfrancesco Burratoa,*, Maria Eliana Polib, Paola Vannolia, Adriano Zanferrarib, Roberto Basilia, Fabrizio Galadinia a Istituto Nazionale di Geofisica e Vulcanologia, Italy b Dipartimento di Georisorse e Territorio, University of Udine, Italy * Corresponding author. Istituto Nazionale di Geofisica e Vulcanologia, Seismology and Tectonophysics Department, Via di Vigna Murata 605, 00143 Rome, Italy. Tel.: +39 06 51860492; fax: +39 06 51860507; e-mail address:
[email protected] (P. Burrato). Abstract We present an overview of the seismogenic sources of northeastern Italy and western Slovenia, included in the last version of the Database of Individual Seismogenic Sources (DISS 3.0.2) and a new definition of the geometry of the Montello Source that will be included in the next release of the database. The seismogenic sources included in DISS are active faults capable of generating Mw > 5.5 earthquakes. We describe the method and the data used for their identification and characterization, discuss some implications for the seismic hazard and underline controversial points and open issues. In the Veneto-Friuli area (NE Italy), destructive earthquakes up to Mw 6.6 are generated by thrust faulting along N-dipping structures of the Eastern Southalpine Chain (ESC). Thrusting along the mountain front responds to about 2 mm/a of regional convergence, and it is associated with growing anticlines, tilted and uplifted Quaternary palaeolandsurfaces and forced drainage anomalies. In western Slovenia, dextral strike-slip faulting along the NW-SE trending structures of the Idrija fault system dominates the seismic release.