The 1998-1999 Pollino (Southern Apennines, Italy) seismic crisis: tomography of a sequence.

In 1998-1999 a seismic sequence occurred in the Southern Apennines, after the moderate size (mb=5.0) 9th September 1998 Pollino earthquake. It lasted about 14 months and was clearly localized to the sole north-west area of the main shock epicenter. Its peculiarity consisted in sudden changes of activity from a series of normal faults with Apenninic (NW-SE) trend and transfer, presumably strike slip, faults with Antiapenninic (NE-SW) and E-W trend. The complexity of the behavior and the different orientations of the activated systems suggest that the area acts as a hinge between the NW-SE trending Southern Apennines and the locally N-S trending Calabrian Arc