GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.1 GNGTS 2023 Earthquakes parameters from citizen testimonies. A retrospective analysis of EMSC database G. Vannucci 1 , P. Gasperini 2,1 , L. Gulia 2 , B. Lolli 1 1 Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna 2 Dipartimento di Fisica e Astronomia, Università di Bologna We computed macroseismic parameters (location and magnitude) using the citizen testimonies, i.e. individual intensity data (IDP) collected and made available by the Lastquake system of the European-Mediterranean Seismological Centre (EMSC, https://emsc.csem.org/ ). IDPs available for earthquakes are selected to eliminate intensities geographically inconsistent with the majority of the data, then they are grouped into reference areas or IDP clusters based on regular grids, equivalent radius of localities or other statistical methods. For each cluster, an intensity value (MDP) equivalent to the assessment for localities in classical macroseismic studies, is computed by statistical methods (average, median, trimmed mean of IDPs). Finally, macroseismic parameters obtained by MDP distribution are compared with the instrumental ones, thus obtaining a retrospective statistical evaluation of their reliability.