Summary of the Abrahamson and Silva NGA Ground Motion Relations
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.
Abrahamson, N.A. and Silva, W.J., 2008, Summary of the Abrahamson and Silva NGA ground motion relations. Earthquake Spectra, v. 24, p. 67-97.
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Email Address Created for Land Exchange Questions
The Southwestern Region Office of Lands and Minerals Management is overseeing and administering the land exchange and appraisal process which includes the 2,422-acre Oak Flat Federal Parcel. All questions about the land exchange and appraisal process should be emailed to SM.FS.rcexinfo@usda.gov
Programmatic Agreement Info
To comply with Section 106 of the National Historic Preservation Act, the Tonto National Forest developed a Programmatic Agreement (PA) and included it in Volume 5, Appendix O of the final EIS. The PA was created in cooperation with the Advisory Council on Historic Preservation, the State Historic Preservation Office, tribes and other consulting parties. The PA contains an agreed upon process for identifying, evaluating and addressing adverse effects to historic properties associated with this undertaking.
To review Volume 5 and the PA, Download Vol 5 PDF, 27 MB.
Forest Service Point of Contact
John Scaggs
Tonto National Forest
john.scaggs@usda.gov
Apache Leap Special Management Area
Apache Leap SMA website