The Database of Individual Seismogenic Sources, DISS 3.1.1: new twists and turns

Abstract

The Database of Individual Seismogenic Sources (DISS) was conceived at the end of the 1990s by a group of scientists at Istituto Nazionale di Geofisica e Vulcanologia. The database was designed to host data about seismogenic source models intended to serve as geological input for ground-shaking SHA applications and was continuously updated since then. In 2005 there was a big turn in this process as we launched a new version of the database (DISS 3) which augmented the database with two innovative categories. The first, now named “Composite Seismogenic Source”, was intended to overcome the inherent difficulties in identifying fault segment boundaries. The second, named “Debated Seismogenic Source”, was devised to host tectonic information about active faults that have been proposed in the literature as potential seismogenic sources but are not fully parameterized or are considered to be not reliable or have been deprecated by subsequent work. In 2005 the database was first made available to the public through a specifically designed web-based GIS application. This new database is now being widely used in various branches of ground-shaking SHA practice and tsunami hazard. The main strength of this database is that it stores fault parameters in a native 3D and flexible conceptual model. Lately, we also developed strategies to make it testable with independent data under a number of different tectonic and seismic hypotheses. During the years, DISS brought together a large amount of published and original data on Italian seismogenic sources having a potential for a magnitude 5.5+ earthquake and is now being extended to the rest of the Euro-Mediterranean area. We present highlights on the identification and characterization of new seismogenic sources in three key-areas in Italy, namely Lombardia/Veneto (Southern Alps), Adriatic Sea, and Abruzzo/Molise (central Apennines). These new sources describe youthful structures of the Alpine south-verging contractional system, the external fold-and-thrust system in the Adriatic offshore, and the extensional domain of the inner central Apennines.