HR: 15:25h
AN: S13E-08 INVITED    [Abstracts]
TI: Estimations of mainshock rates based on interevent-time statistics
AU: * Hainzl, S
EM: hainzl@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473, Germany
AB: The statistics of time delays between successive earthquakes has recently been shown to provide useful information about the properties of earthquake clustering, in particular, about the percentage of mainshocks in the catalog (background fraction) [Hainzl et al., BSSA, 2006]. The shape of the interevent-time distribution can be approximated by the gamma distribution where the background fraction is simply determined by the variance and mean value. Although detailed analytical analysis of Saichev & Sornette [JGR, 2007] shows that the distribution for the ETAS-type mainshock-aftershock activity is more complicated, the simple approximation seems to work for a large parameter range. This is verified with synthetic simulations where the underlying frequency-magnitude distribution of the background activity is successfully reconstructed by this method. Here, I will compare the method with "classical" declustering algorithms like the Reasenberg algorithm and the statistical declustering based on the explicit estimation of the ETAS parameters and will discuss its advantages and shortcomings.
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
SC: Seismology [S]
MN: 2007 Fall Meeting