Local and Duration Magnitude Determination for the Italian Earthquake Catalog, 1981-2002

Abstract

In the present work, we update magnitude estimates of the instrumental catalogue of 99,780 Italian earthquakes that occurred during 1981-2002.The catalog contains a large data set of P-and S-arrival times and accurate earthquake locations.We derive duration magnitude estimates from linear regression between local magnitude calculated from Mediterranean Very Broadband Seismographic Network (MedNet) and the corresponding seismic-signal durations at the national network Rete Sismica Nazionale Centralizzata (RSNC).We introduce a station correction factor Sc j because of most of the stations located in southern Italy show large residuals that appear to be of regional importance.The relation obtained:Log M 0 ‫מ‬ M L and M W ‫מ‬ M L relations are also computed in the range of 3.5-5.8from regional centroid moment tensor estimation of medium-strong Italian earthquakes, by linear regressions.We obtained best least-square fits for:Log M ‫ס‬ ‫ע(81.1‬0.06) ⅐ M ‫ם‬ 10.92.