In 1906, a massive magnitude 7.9 earthquake ruptured the entire San Andreas Fault in Northern California. Photo courtesy of U.S. Geological Survey		Main: The 1906 Earthquake Birth of Earthquake Science Bay Area Preparedness P-wave Warnings Map: Major Bay Area Faults Slide Show: Deconstructing the 1906 Quake Interactive: Will This Building Stand? Lesson Plan: History Through First-Person Accounts