Accelerations near faults that have moved during moderate-sized earthquakes

Peak ground accelerations recently recorded within 10-15 km of faulting during moderate-sized earthquakes (m = 4 to 6) are significantly underestimated by many, if not most, of the empirical acceleration-distance relations commonly used in seismic engineering. The recent data show a rapid decrease of peak acceleration with increasing distances (at a rate between r^-1.4 and  r^-I.8) beyond 5 to 20 km and suggest a less rapid rate of attenuation closer to the causative fault.