A statistical study of the MW 5.3 Valandovo (northern Macedonia) earthquake seismic sequence

Studying of the space-time distribution of earthquakes is very important for understanding the physics of the earthquake generation process. The 2009 Valandovo earthquake, northern Macedonia, with moment magnitude MW 5.3, was preceded by a foreshock sequence and followed by an intensive aftershock activity. We analyse the space-temporal pattern of earthquake distribution in the foreshock and aftershock sequences of the main event. We find short-distance clustering in both the pre-shock and aftershock period. The temporal distribution of foreshocks shows non-random features. Although dominated by the classic power law decay in time, the aftershocks suggest the existence of secondary aftershock sequence.