The California earthquake of 1906 ranks as one of the most significant earthquakes of all time. Rupturing the northernmost 296 miles of the San Andreas fault from northwest of San Juan Bautista to the triple junction at Cape Mendocino, the earthquake confounded contemporary geologists with its large, horizontal displacements and great rupture length.
At almost precisely 5:12 a.m., local time, a foreshock occurred with sufficient force to be felt widely throughout the San Francisco Bay area.
The great earthquake broke loose some 20 to 25 seconds later, with an epicenter near San Francisco.
Violent shocks punctuated the strong shaking which lasted some 45 to 60 seconds.
The earthquake was felt from southern Oregon to the south of Los Angeles and inland as far as central Nevada.
The highest Modified Mercalli Intensities (MMI's) of VII to IX paralleled the length of the rupture, extending as far as 80 kilometers inland from the fault trace.