San Andreas Fault

San Andreas Fault, geological fault zone in California, United States, stretching north-west for about 970 km (600 mi), from the Imperial Valley in southern California to Point Arena on the northern coast of California. The zone marks the boundary between the North American and Pacific tectonic plates. Earthquakes occur along it because of obstacles to the steady, even movement of the two plates as they slide past each other. The San Andreas Fault was responsible for the San Francisco earthquake of 1906, which killed 700 people, and the Los Angeles earthquake of 1994.