%A Ilya Zaliapin
%A Andrei Gabrielov
%A Vladimir Keilis-Borok
%A Henry Wong
%J Physical Review Letters
%T Clustering Analysis of Seismicity and Aftershock Identification
%X We introduce a statistical methodology for clustering analysis of seismicity in the time-space-energy domain and use it to establish the existence of two statistically distinct populations of earthquakes: clustered and nonclustered. This result can be used, in particular, for nonparametric aftershock identification. The proposed approach expands the analysis of Baiesi and Paczuski [Phys. Rev. E 69, 066106 (2004)] based on the space-time-magnitude nearest-neighbor distance η between earthquakes. We show that for a homogeneous Poisson marked point field with exponential marks, the distance η has the Weibull distribution, which bridges our results with classical correlation analysis for point fields. The joint 2D distribution of spatial and temporal components of η is used to identify the clustered part of a point field. The proposed technique is applied to several seismicity models and to the observed seismicity of southern California.
%N 1
%V 101
%D 2008
%R doi:10.1103/PhysRevLett.101.018501
%I The American Physical Society
%L epos195