The San Andreas Fault is a geologic fault zone between two tectonic plates that runs from San Francisco south to San Diego in California. It is an area of frequent earthquakes caused by the plates sliding past each other. It is so called because it runs along the San Andreas Valley.
The San Andreas fault was brought dramatically to world attention in 1906 when sudden displacement along the fault produced the great San Francisco earthquake and fire. This earthquake was but one of many that have resulted throughout its life of about 15-20 million years.
The entire San Andreas fault system is more than 800 miles long and extends to depths