Italian Parametric Earthquake Catalogue CPTI15, version 2.0

Abstract

More than thirty years ago, in 1985, the compilation of the "Catalogo dei Terremoti Italiani dall’anno 1000 al 1980" (Catalogue of Italian Earthquakes from the year 1000 to 1980) in the framework of the “Progetto Finalizzato Geodinamica” was completed and published by Daniele Postpischl (Postpischl, 1985a). The Working Group that authored the catalogue had the goal of verifying the information on Italian earthquakes listed in different available catalogues, in particular the ENEL (1977) one, and compile a new, state-of-the-art catalogue. At the conclusion of that work, which had appeared as preliminary with respect to the initial goal, the entire, almost forgotten subject area of historical seismology had emerged and “the first concrete advancements in the still long course of the research, towards the development of final products” were represented by the catalogue and the monographs on large earthquakes collected in the “Atlas of isoseismal maps of Italian earthquakes” (Postpischl, 1985b). The possibility of having final products was rapidly abandoned, as testified by the long process that has led to the current version of the Italian Parametric Earthquake Catalogue, which inherited that epoch. Through years the possibilities of improving the knowledge on earthquakes already known to the seismological tradition have been – and still are – manifold, and new research strategies have developed. The new version of the Catalogue, after thirty years, is a further important contribution to the advancements of the understanding of the seismicity of the Italian territory, the definition of seismogenic processes, the identification and characterization of active structures and the improvements of seismic hazard assessment. The first version of the Parametric Catalogue of Italian Earthquakes (Catalogo Parametrico dei Terremoti Italiani, CPTI99; CPTI Working Group, 1999) was published in July 1999. It aimed at unifying and homogenizing, by using the same parameterization procedures for all the events, the information on Italian earthquakes since then produced by different investigators or reported by different catalogues (NT4.1, Camassi and Stucchi, 1997; CFTI 1 and 2, Boschi et al., 1995; 1997). In 2004, the second version CPTI04 (CPTI Working Group, 2004) was published as the catalogue to be used in the framework of the Italian seismic hazard assessment MPS04 (MPS Working Group, 2004; Stucchi et al., 2011). CPTI04 was indeed new only as concerns the 1981-2002 portion, the remaining portion being the same as CPTI99 with the exception of the conversion of Ms to Mw with empirical relationships. Some experimental and/or partial version were then released within INGV or to specific research projects. The third published version, named CPTI11 (Rovida et al., 2011), was released in December 2011. Together with a remarkable update of the input data, both macroseismic (collected in the 2011 release of Italian Macroseismic Database DBMI11; Locati et la, 2011) and instrumental, the most important innovations with respect to previous versions regarded the catalogue structure, consisting of three sets of earthquake parameters, i.e. macroseismic, instrumental, and preferred ones, and the inclusion of records related to many fore- and after-shocks. Nonetheless, for time constraints only studies contributing macroseismic data published before 2007 were taken into account and neither the empirical conversion relations for homogenizing instrumental magnitudes to Mw nor the calibration used to assess parameters from macroseismic data - except the experimental application of the method of Bakun and Wentworth (1997) to a few offshore earthquakes - were updated. Thanks to the improved methodologies developed in the framework of some European projects and, mostly, to the wealth of new macroseismic data published in the last years, together with revised calibrations of instrumental magnitudes, in 2016 a new important update of the catalogue, as well as a new version of the companion macroseismic database DBMI, was released as CPTI15. The first version (v1.5) of CPTI15 (Rovida et al., 2016) has later been updated, with the extension of its time-coverage to the years between 2015 and 2017, with the inclusion of revised parameters of some earthquakes between 2012 and 2014, and with the correction of few compilation errors. The present document is then updated to version 2.0. The changes in the catalogue are detailed in Section 4.