Damage Probability Matrices for eight historic centers after the 2009 L'Aquila earthquake

n this paper, the results of a damage reconnaissance activity carried out on eight minor historic centers of Abruzzi after the 6.3 Mw L’Aquila earthquake, occurred on the 6th of April 2009 in the central area of Italy, is presented. In the first part, minor historic centers belonging to the region interested by the earthquake are described. The main morphological features of these centers, to be ascribed to an historical urban development often carried out according to extemporaneous logics, are discussed. Moreover, the main construction typologies are presented: these are made of poor masonry buildings with many fragility sources and are the result of several transformations and stratifications carried out since the medieval age in order to comply with inhabitants needs, but, mostly, not with structural/seismic matters. The second part of the paper is focused on the occurred damage scenarios. The most frequent failure mechanisms of macroelements are shown and the observed damage is classified according to the grades introduced by Grünthal for the definition of the EMS-98 European Macro-seismic scale. Finally, the revealed frequencies of the observed damage grades are organized in damage probability matrices. These are provided as a useful tool able to quantify effectively the occurred damage and to predict the potential losses that have to be expected for similar historical centers in case of future seismic events.