Appendix I

This paper contains ground-motion prediction equations (GMPEs) for average horizontal-component ground motions as a function of earthquake magnitude, distance from source to site, local average shear-wave velocity, and fault type.

The purpose of this study was to gather and analyze previously unused data that led to improved locations for the 1906 (Ms 6.2), 1910 (Ms 6.0) and 1912 (Ms 6.2) northern Arizona earthquakes. Both ground shaking intensity patterns and instrumental data were used. The objective is to provide epicenter locations accurate enough to allow planners to decide what ground acceleration levels are most appropriate for northern Arizona.

The commonly used Uniform Hazard Spectrum (UHS) is shown here to be an unsuitable target for this purpose, as it conservatively implies that large-amplitude spectral values will occur at all periods within a single ground motion. An alternative, termed a Conditional Mean Spectrum (CMS), is presented here.

Starting with geological data, this paper estimates the seismicity for applications in seismic risk studies. The rate at which seismic moment is released can be estimated on a fault when the slip rate is known. Then, provided all of the deformation is released seismically, by assuming the relative frequency of different sizes of earthquakes, the absolute frequency of events can be obtained.