  The data analysis of aftershock events of L Aquila earthquake in Apennines
following the main 6.3 Mw event of April 6, 2009 has been carried out by
standard statistical geophysical tools. The results show the heterogeneity of
seismic activity in five different geographical sub-regions indicated by
anomalous critical indices of power law distributions: the exponents of the
Omori law, the b values of Gutenberg-Richter magnitude-frequency distribution,
and the distribution of waiting times. The heterogeneous distribution of
dynamic stress and a different morphology in the five sub-regions has been
found and two anomalous sub-regions have been identified.
