From Wikipedia, the free encyclopedia

Note that Diablo Fault redirects here.

For recent activity in the region shown on this map see the USGS map for this location. The "live" maps will also show all of the names of faults shown on the map as you rollover with the cursor.

The Calaveras Fault is located in northern California in the San Francisco Bay Area and is a strike slip fault . It branches off to the east of its more famous (and much longer) sister fault, the San Andreas Fault in the vicinity of Hollister, California. Between the San Andreas Fault and the Calaveras Fault lies the Hayward Fault Zone, which branches off the Calaveras Fault east of San Jose, California. To the east lies the Clayton-Marsh Creek-Greenvile Fault and their northern and southern extensions via other faults. These four fault structures are the major faults in California at the latitude of San Francisco.

To the north, the Concord Fault is not aligned with the Calaveras Fault, and small earthquakes occur in the gap between faults, mostly in Alamo, California to relieve stresses generated by the displacement between the two faults. Stresses are also produced by offset and converging slip-strike motions between the Caliveras and Clayton-Marsh Creek-Greenvile Fault that continue to elevate Mount Diablo. The compressive pressure has caused the creation of significant thrust fault nearby on the western slope of the mountain, the Diablo Fault[1], the most active of its kind in the region and which is also capable of producing significant local earthquakes affecting the Alamo-Danville area.

As the Pacific Plate moves slowly northward under the forces of plate tectonics, the several faults shown on the map above are both locked and stressed and periodically one will rupture over some portion of its length, releasing energy in the form of earthquakes. Most of the earthquakes are small and fairly frequent (in a geological time scale). The last truly major earthquake in the region was the 1906 San Francisco Earthquake, its 16 foot (5meter) fault movement on the San Andreas causing substantial destruction of masonry buildings prior to the subsequent and far more destructive fire in the city. Much of the substantial destruction due to ground motion in the larger region (other than the extreme devastation of Santa Rosa) was little noted in the reporting.

Some of the cities which the Calaveras Fault passes through or near are: Alamo, Danville, San Ramon, Dublin, Pleasanton, Sunol, Milpitas, San Jose, Gilroy, and Hollister.

• Bernal Subbasin
• Tesla Fault