Appendix I

Here we are concerned with solving for the long term average values of these parameters for the state of California. My primary data source is a catalog of 1850-2006 M  4.0 seismicity compiled with Tianqing Cao (Appendix H). Because earthquakes outside of the state can influence California I consider both earthquakes within the state and within 100 km of the state border (Figure 1).

California’s 35 million people live among some of the most active earthquake faults in the United States. Public safety demands credible assessments of the earthquake hazard to maintain appropriate building codes for safe construction and earthquake insurance for loss protection. Seismic hazard analysis begins with an earthquake rupture forecast—a model of probabilities that earthquakes of specified magnitudes, locations, and faulting types will occur during a specified time interval.

We mapped and characterized Quaternary site conditions using shear-wave-velocity (Vs)-profile data for basins along the Wasatch Front urban corridor to provide a basis for estimating soil response during earthquake ground shaking.

Ground-motion prediction (attenuation) models predict the probability distributions of spectral acceleration values for a specified earthquake event. In this article a large number of strong ground motions are used to empirically estimate these correlations, and nonlinear regression is used to develop approximate analytical equations for their evaluation.

We present tectonic reconstructions and an accompanying animation of deformation across the North America–Pacific plate boundary since 36 Ma.

This study presents effective probabilistic procedures for evaluating ground-motion hazard at the free-field surface of a nonlinear soil deposit located at a specific site.

We document the precise sizes, but not the dates, of the six latest offsets across the San Andreas fault at Wallace Creek, California. Three and perhaps four of these, including the latest in 1857, show dextral offset of 7.5–8 m. The third and fourth offsets, however, are just 1.4 and 5.2 m. The predominance of similar offsets for the latest six events suggests that the fundamental properties of the fault system that control slip size do not vary greatly from event to event. The large offsets imply that ruptures involving this site are typically more than 200 km long.

In areas of broadly distributed extensional strain, the back-tilted edges of a wider than normal horst block may create a synclinal-horst basin. Three Neogene synclinal-horst basins are described from the southern Rio Grande rift and southern Transition Zone of southwestern New Mexico,USA

These maps show an estimate of the likelihood of earthquake ground motions, based on a probabilistic seismic hazard analysis. Such analysis incorporates seismic and geologic information to consider the probability of all possible damaging earthquakes, calculates the potential range of ground motions for each potential earthquake, and arrives at a level of ground shaking that has a given probability, using the formulation first developed by Cornell (1968).

This report presents the results of probabilistic seismic hazard analyses for use in screening/scoping-level dam safety and/or risk assessments of Granite Reef Diversion and Theodore Roosevelt Dams in southern Arizona. The purpose of these evaluations is to estimate the levels of ground motions, which will be exceeded at specified annual frequencies (or return periods), at the damsites.