A Comparative Analysis of Four Commonly Implemented Declustering Algorithms

Abstract

Abstract Declustering of earthquake catalogs, that is determining dependent and independent events in an earthquake sequence, is a common feature of many seismological studies. While many different declustering algorithms exist, each has different performance and sensitivity characteristics. Here, we conduct a comparative analysis of the four most commonly used declustering algorithms: Garnder and Knopoff (1975), Reasenberg (1985), Zhuang et al. (2002), and Zaliapin and Ben-Zion (2008) in four different tectonic settings. Overall, we find that the Zaliapin and Ben-Zion (2008) algorithm effectively removes aftershock sequences, while simultaneously retaining the most information (i.e. the most events) in the output catalog and not significantly modifying statistical characteristics (i.e. the Gutenberg Richter b-value). Both Gardner and Knopoff (1975) and Zhuang et al. (2002) also effectively remove aftershock sequences, though they remove significantly more events than the other algorithms. By contrast, Reasenberg (1985) only effectively removed aftershocks in one of the test regions.