
Annals of Geophysics 2010
A statistical study of aftershock sequencesDOI: 10.4401/ag4645 Abstract: A comprehensive statistical study of the phenomenology of aftershock sequences is made in this paper. The spatial distribution of aftershocks indicates that they are mainly crustal events; however, deeper sequences also take place. The analysis of the distribution of aftershocks in 15 sequences with respect to time and magnitude leads to the statistical confirmation of a set of phenomenological laws describing the process, namely, the timefrequency law of hyperbolic decay of aftershock activity with time, the magnitude stability law, and the exponential magnitude frequency distribution. The hypotheses involved are checked. The grouping of data and the statistical methods employed are chosen according to some basic well·confirmed assumptions regarding the nature of the process.
