Identifying space-time clustering properties of the 1983-1997 Irpinia-Basilicata (Southern Italy) seismicity

The fractality of the earthquake sequence (1983-1997) of Irpinia-Basilicata (Southern Italy), one of the most seismically active regions of the Medite rranean area, has been analysed by temporal and spatial fractal tools. The fractal exponent alpha, estimated by the Allan Factor method, characterises the time-clustering behaviour of the set of earthquakes, while the correla tion dimension D-C, calculated by means of the correlation integral method, gives information on the spare-clustering behaviour of the sequence of sei smic events. Analysing the variations of both the parameters, we recognised the presence of a strong space-time clusterisation associated with the maj or events that occurred in the investigated area. (C) 2001 Elsevier Science B.V. All rights reserved.