The Rimini earthquake of 17th May 1916 (Italy): from historical data to seismic parameters.

Abstract

The earthquake of 17th May 1916 at 12:50 hours (GMT) is the first event of a seismic sequence that struck the northeastern coast of Italy (in particular the towns of Rimini and Cattolica) and lasted until December of the same year. The Catalogue of Strong Italian Earthquakes (http://storing.ingv.it/cfti4med/) classifies 132 locations in regard to this earthquake which had a maximum and epicentral intensity equal to the VIII degree of MCS scale, with magnitude equivalent to 5.8. During the First World War, the ISS bulletin was unpublished and the available epicentral location was derived only from macroseismic analysis. In this work we col-lected the bulletins available from Euro-Mediterranean observatories and we performed the first instru-mental location for this event. This event is amongst the high priority earthquakes included in the Euro-seismos project (http://storing.ingv.it/es_web). In the database of the SISMOS Project – INGV (http://sismos.ingv.it) 50 recordings from 20 different Euro-Mediterranean observatories are available today for this earthquake. The analysis of all these data allowed us to obtain a reassessment of the main seismological parameters (MW, MS) and a re-location of the epicenter. Preliminary results suggest an east forward migration of previous location of the epicenter and a probable underestimation of the magnitude consigned into the catalogues. Special attention was devoted to determining the error margins of the obtained results. A comparison between these parameters and that extrapolated from macroseismic data will be discussed.