Individual faults can't produce a Gutenberg-Richter earthquake recurrence

Individual faults within a region cannot have a Gutenberg-Richter recurrence if the total of earthquakes within the region follow a Gutenberg-Richter recurrence. Few faults have produced an adequate number of earthquakes to establish the nature of recurrence on them. Broad seismic regions, however, for which there is a statistically viable earthquake data set, have been shown to obey a Gutenberg-Richter recurrence with a slope of about 1. A Gutenberg-Richter recurrence is often assumed for faults in probabilistic seismic hazard analyses. The requirement that individual faults cannot produce earthquakes with this recurrence casts doubt on the validity of such probabilistic methods. Errors in probabilistic seismic hazard analysis tend to be amplified in the calculation of rare earthquake probabilities and it is these rare earthquakes for which critical facilities must be designed. Therefore, sole use of probabilistic seismic hazard analysis for critical facilities is not recommended.