The 6 May 1976 Friuli earthquake: re-evaluating and consolidating transnational macroseismic data

Abstract

The aim of this paper is to propose the creation, in terms of European Macroseismic Scale (EMS-98), of the entire macroseismic fi eld of the 6 May 1976 Friuli earthquake. Only forty odd years have passed, and nothwithstanding that there is a huge quantity of existing data, it was still disturbing to fi nd that much of the original data are missing and probably lost forever. Efforts have, therefore, been made to fi nd additional and still unknown primary data. For the majority of the collected national data sets, a reevaluation was, then, possible. This study presents the comprehensive macroseismic data set for 14 European countries. It is, to our knowledge, one of the largest European data sets, consisting of 3423 intensity data points. The earthquake was felt from Rome to the Baltic Sea, and from Belgium to Warsaw. The maximum intensity 10 EMS-98 was reached in eight localities in Friuli (Italy). Compared to previous studies, the Imax values have changed from country to country, in some cases being lowered due to methodological differences, but in the case of three among the most hit countries, Imax is now higher than in the previous studies, mainly due to the new data.