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Decustering , Rates, and b -values or Declustering : the Necessary Evil of Statistical Seismology. Andy Michael. Gardner and Knopoff Declustering. Method: Gardner and Knopoff (BSSA, 1974): Magnitude-dependent spatial circles and time windows
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Decustering, Rates, and b-values or Declustering: the Necessary Evil of Statistical Seismology Andy Michael
Gardner and KnopoffDeclustering Method: Gardner and Knopoff (BSSA, 1974): Magnitude-dependent spatial circles and time windows Problem: Spatial circles too small for large earthquakes Solution: Use radii based on fault rupture lengths from Wells and Coppersmith (BSSA, 1994)
SCSN M≥2 1984-2010 Radii = Uhrhammer ΔT = 1 day Nmain=32490, p=0
SCSN M≥2 1984-2010 Radii = G-K ΔT = 1 day Nmain=26992, p=3*10^-7
SCSN M≥2 1984-2010 Radii = G-K ΔT = 3 days Nmain=19494, p=0.002
SCSN M≥2 1984-2010 Radii = G-K ΔT = 7 days Nmain=12892, p=0.56
SCSN M≥2 1984-2010 Radii = G-K ΔT = 100 days Nmain=1185, p=0.89
Issues for UCERF3: Decluster and then estimate rates or Estimate rates using an ETAS model directly. If declustering then which method or how many methods? National Maps use Gardner-Knopoff which lowers b-value ETAS uses the same b-value for background and clusters Could decluster with a stochastic ETAS approach and maintain the same b-value, good for ETAS but bad for National Maps Could decluster with Gardner-Knopoff and then do ETAS with a different magnitude-frequency distribution that combines to the correct totaldistribution.