title: Origin and nonuniversality of the earthquake interevent time distribution.
abstract: Many authors have modeled regional earthquake interevent times using a gamma distribution, whereby data collapse occurs under a simple rescaling of the data from different regions or time periods. We show, using earthquake data and simulations, that the distribution is fundamentally a bimodal mixture distribution dominated by correlated aftershocks at short waiting times and independent events at longer times. The much-discussed power-law segment often arises as a crossover between these two. We explain the variation of the distribution with region size and show that it is not universal.
authors.affiliation: School of GeoSciences, University of Edinburgh, Grant Institute, The King's Buildings, West Mains Road, Edinburgh EH9 3JW, United Kingdom. s.touati-2@sms.ed.ac.uk
authors.forename: Sarah
authors.initials: S
authors.lastname: Touati
authors.forename: Mark
authors.initials: M
authors.lastname: Naylor
authors.forename: Ian G
authors.initials: IG
authors.lastname: Main