ИСТИНА

The effect of various preliminary processing methods of seismic catalogues on seismic hazard assessment is studied. The impact of declustering, i.e. the removal of dependent events, and the choice of the completeness magnitude was investigated. The catalogues of the Kamchatka and Caucasus regions were used for the analysis, because synthetic catalogues may not show the real features of regional seismicity. The declustering impact on seismic hazard calculations is illustrated by the examples of Kamchatka and Caucasus regions, where probe sites were selected. Three methods of declustering are considered: there is a different number of events in the catalogues after their application. The plotted hazard curves indicate a complex "interaction" of catalogue declustering with the choice of the completeness magnitude, since both of them affect the b-value, and it is not always possible to predict in advance whether this leads to an increase or a decrease in the estimate of b-value. The method of declustering, which leaves most events in the catalogue, does not always give the highest hazard estimate. In this regard, it is necessary to note again that it should be treated with special care and attention to declustering of catalogues. At least, it should be taken into account that this procedure can affect the final result unpredictably