Supplementary Figure FS1. (a) Incremental magnitude-frequency plot of the
post-1979 ANSS catalog that begins to roll off around M=5. The b-value of the
whole catalog above M=5.0 is b=1.24 by maximum likelihood. In (b) the
maximum curvature method of Wiemer and Wyss [2000] is applied, and the
magnitude of completeness (Mc) is estimated at M=4.85. In (c) the goodness-offit method of Wiemer and Wyss [2000] is applied for b-values of b=1.1 and b=1.2,
which results in estimates of Mc ranging from M=4.6 to M=5.1 (using the
criterion that 90% of the data above Mc are fit are fit by the b-value model). In (d)
the b-value stability model of Cao and Gao [2002] is used with the criterion
recommended by Woessner and Wiemer [2005] that the difference between bvalue calculated above a cut-off magnitude (blue curve) and average b-value (red
curve) be less than the calculation uncertainty [Shi and Bolt, 1982]. This method
gives Mc=4.7.
References
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Shi, Y., and B. A. Bolt (1982), The standard error of the magnitude frequency b-value, Bull.
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Wiemer, S., and M. Wyss (2000), Minimum magnitude of complete reporting in earthquake
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Woessner, J., and S. Wiemer (2005), Assessing the quality of earthquake catalogues: Estimating
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