Appendix I

This paper describes the development and application of a new method for generation of realistic synthetic earthquake time histories compatible with multiple-damping design spectra. The effectiveness of this new method is demonstrated by applying it to adjust actual earthquake time histories to match the design spectra while minimizing perturbations on their characteristics. The paper also demonstrates that seismic responses of structures based on such spectrum-compatible realistic time histories are consistent with those obtained from analyses using an ensemble of time histories.

Because of increased public interest and concern about expected losses from future earthquakes in California, the National Earthquake Prediction Evaluation Council recommended that the probability of occurrence of large (magnitude 7 or greater) earthquakes in California be evaluated. In response to this recommendation, the U.S. Geological Survey formed the Working Group on California Earthquake Probabilities.

A tectonic boundary should be defined by changes in tectonic elements. Tectonic elements would include such parameters as structural style, stress orientations, volcanism, heat flow, seisrnicity and changes in crustal thickness. Examination of these tectonic elements for the southern Colorado Plateau suggests that the southwestern part of the physiographic plateau appears to be tectonically part of the Basin and Range province.

A computer code (RASCAL) has been developed to provide realistic predictions of ground motion parameters for applications to earthquake engineering risk assessment.

Data describing the locations, slip rates, and lengths of Quaternary faults are the primary basis in this work for constructing maps that characterize seismic hazard in California. The expected seismic moment M^e₀ and the strength of ground shaking resulting from the entire rupture of each mapped fault (or fault segment) are estimated using empirical relations between seismic moment M₀, rupture length, source to site distance, and strong ground motions.

The Sugarloaf fault is a slightly arcuate, northwest-southeast trending fault located near the junction of Mesquite Wash and Sycamore Creek. The fault was identified by Fugro (1981), which considered the fault in itsMCE analysis for Stewart Mountain Dam because of the evidence for possible Quaternary activity along the structure.

Increasingly, fault slip rates are being used to constrain earthquake recurrence relationships for site-specific probabilistic seismic hazard (ground motion) assessments. This paper shows the sensitivity of seismic hazard assessments to variations in recurrence models and parameters that incorporate fault slip rates.

The Colorado Plateau is a major tectonic and physiographic province in the southwestern United States which has been relatively stable during the Phanerozoic, but has been epeirogenically uplifted about 2 km in the Cenozoic.

This report presents the results of a reconnaissance analysis of Quaternary faulting in central Arizona, conducted for the U.S. Bureau of Reclamation. The goal of this study has been to thoroughly delineate locations of possible Quaternary faulting in the area surrounding existing and potential dam sites in central Arizona.

The Mogollon (muh-ge-own) Escarpment of central Arizona is one of the State's spectacular natural attractions, especially when viewed from the rim of its precipitate cliffs.