Detrended fluctuation analysis of the spatial variability of the temporal distribution of Southern California seismicity

Using the seismic catalog, relocated by Richards-Dinger and Shearer [J. Geophys. Res. 105 (2000) 10939], the analysis of the spatial variation of the time-clustering properties of the seismicity of southern California has been performed. The time span of the analyzed catalog is from 1981 to 1998. The analysis is performed by using the detrended fluctuation analysis (DFA) of the interevent intervals, that permits the identification of correlated temporal structures in time series, even in presence of trends or nonstationarities. The significance of the estimates of the scaling exponents, performed by the DFA, is obtained by analyzing the time dynamics of surrogate versions of the data, generated by randomly shuffling the order of the interevent intervals. The analysis carried out in the present study could provide better understanding of the time-clustering properties of the area, characterized by the presence of three different depth ranges.