Consensus indicates that faults follow power-law scaling, although significant uncertainty remains about the values of important parameters. Combining these scaling relationships with power-law scaling relationships for earthquakes suggests that intraplate earthquake recurrence interval scales with fault length. Regional scaling data may be locally calibrated to yield a site-specific seismic hazard assessment tool. Scaling data from small faults (those that do not span the seismogenic layer) suggest that recurrence interval varies as a negative power of fault length. Due to uncertainties regarding the recently recognized changes in scaling for large earthquakes, it is unclear whether recurrence interval varies as a negative or positive power of fault length for large faults (those that span the seismogenic layer). This question is of critical importance for seismic hazard assessment. ¿ American Geophysical Union 1994