Local relations for convertingMLtoMWin Southern-Western Balkan region

Compilation of a homogenous earthquake catalogue, by expressing the size of the earthquakes in a unified magnitude scale, is an important tool for the seismic hazard evaluation. The most reliable and useful scale of magnitude to be chosen as the common measure of earthquake size, for both historically known and the instrumentally recorded events, is the moment magnitude, MW . We investigate the empirical relationships between local magnitudes ( ML ) calculated by the seismological agencies operating in the Western Balkan countries, and the relevant moment magnitude MW , derived from the moment tensor analysis of medium-strong Western Balkan earthquakes. As result, regression relations converting ML to MW for these countries have been derived. Based on the proposed relations, an estimate of MW which can be considered as a unified magnitude scale can be calculated for each earthquake of the regional catalogue.