This report begins with a review of the physical and
experimental bases for quantative description of earthquake
occurrence rates and geological recurrence rates, to describe
the amplitudes and the shape of the magnitude occurrance rate
curves for earthquakes in a region. It considers the selection
of the maximum earthquake, the limitations of geological
observations and the most important sources of uncertainty. Then
it presents the concept of uniform risk spectrum with the most
recent refinements in this methodology, including more detailed
description of the earthquake source zones, and the
uncertainties of estimating a summary of the method for
generating artificial accelerograms for use in engineering
design. The artificial accelerogram can be derived either
starting from the uniform risk spectrum computed by NEQRISK
program, or by using independently determined Fourier amplitude
spectra of the desired strong ground motion.; When the seismic
risk at a site is dominated by the presence of an active fault