San Andreas Fault Zone, California: M ≥5.5 Earthquake History
The San Andreas fault zone has been a very significant source of major California earthquakes. From 1812 to 1906 it generated four major earthquakes of M ~7 or larger in two pairs on two major portions of the fault. A pair of major earthquakes occurred on the central to southern region, where the 1857 faulting overlapped the 1812 earthquake faulting. A pair of major earthquakes occurred on the northern region, where the 1906 faulting overlapped the 1838 earthquake faulting. Also, earthquakes of M ~7 occurred in the San Francisco Bay area on the Hayward fault in 1868 and the Santa Cruz Mountains near Loma Prieta in 1989 and on the Imperial fault near the border with Mexico in 1940.
Toppozada, T.R., Branum, D.M., Reichle, M.S., and Hallstrom, C.L., 2002, San Andreas fault zone, California: M ≥5.5 earthquake history: Bulletin of the Seismological Society of America, v. 92, p. 2555-2601.
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.firstname.lastname@example.org
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.