San Andreas Fault. Aerial photograph of the San Andreas fault crossing the Carrizo Plain about 450 km (300 miles) south of San Francisco and 160 km (100 miles) north of Los Angeles California, USA. One of the world's great seismic faults the San Andreas extends almost the full length of California and is responsible for major earthquakes. A linear valley has eroded along the main track of the fault, running down the center of the photograph. The desolate landscape consists of pressure ridges formed as a result of hundreds of fault movements.