The San Andreas Fault, the boundary between the North American tectonic plate and the Pacific tectonic plate, primarily affects California from the state's northwestern coast down to the Mexican border. The earthquakes that result from the movement of the fault line create aftershocks that have been felt hundreds of miles away in Nevada, New Mexico, and Mexico.
On Land
The visible portions of the San Andreas Fault start north of San Francisco in a town called Point Arena and progress southeast to the Salton Sea, which lies near the Mexican border. The 625 visible miles of the fault directly impact every city that lies directly on and around it.
At Sea
Scientists who study the San Andreas Fault speculate that the fault line continues underwater for another 400 miles northwest of Point Arena and another 1,000 miles along the Gulf of California. These distances bring potential earthquake activity to southern Oregon and Mexico, and the underwater aspect creates the possibility of tsunamis.
"Big Bend"
One segment of the San Andreas Fault bends and follows east for six miles. This area, about 60 miles northwest of Los Angeles, is referred to as the "Big Bend" area and is prone to earthquakes. The 1857 Fort Tejon earthquake, with an 8-plus magnitude, and the 1971 San Fernando earthquake, magnitude 6.6, are both associated with the "Big Bend" area.
San Jacinto Fault
The San Jacinto Fault is a direct extension of the San Andreas Fault system, moving slightly more south, running directly through San Bernardino, and passing under Colton's four-level freeway interchange.
Recreation
Despite the dangers of a potential earthquake, the San Andreas Fault boasts copious natural beauty, which attracts many visitors. Parks such as Point Reyes National Seashore and Joshua Tree National Park are known for their positioning along the fault line.
Interactive Map
Geology.com features an interactive map of the San Andreas Fault (see Resources). Users can zoom in and out to get a better image of the fault line.
Tags: Andreas Fault, fault line, another miles, Bend area, Jacinto Fault
