Appendix I

Paleoseismological data constrain the age, location, and associated magnitude of past surface-rupturing earthquakes; these are critical parameters for developing and testing fault behavior models and characterizing seismic hazard. We present new earthquake evidence and radiocarbon analyses that refine the chronology of the six most recent earthquakes that ruptured the south-central San Andreas fault in the Carrizo Plain (California, United States) at the Bidart Fan site.

In previous ground-motion models, the range of applicability of the empirical ground-motion models was based on the range covered by the available empirical data set; however, in hazard studies, the ground motion must be computed for all relevant earthquakes, so the limits on the range of applicability were often ignored. To address this issue, the Next Generation Attenuation (NGA) project required the developers of the models to extrapolate their models such that they are applicable to all crustal earthquakes relevant for seismic hazard analyses in California.

Using a database of 655 recordings from 58 earthquakes, empirical response spectral attenuation relations are derived for the average horizontal and vertical component for shallow earthquakes in active tectonic regions. A new feature in this model is the inclusion of a factor to distinguish between ground motions on the hanging wall and footwall of dipping faults.

North–south-striking and west-dipping Basin and Range province normal faults form the western edge of the Sierra Madre Occidental plateau in northeastern Sonora.

This detailed field survey of the previously undocumented 1887 earthquake rupture zone along the Otates fault includes mapping the rupture scarp and measurements of surface deformation at 25 sites.

This draft technical memorandum has been prepared to summarize hydrogeologic data and provide an assessment of hydrogeologic conditions and water uses in the vicinity of the Whitford, Silver King, and Happy Camp sites (Near West area) for the RCM Tailings Prefeasibility Study (PFS).


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