The
San Andreas Fault is a continental
transform fault that extends roughly 1300 km (810 miles) through
California. It forms the
tectonic boundary between the
Pacific Plate and the
North American Plate, and its motion is
right-lateral strike-slip (horizontal). The fault divides into three segments, each with different characteristics and a different degree of earthquake risk, the most significant being the southern segment, which passes within about 35 miles of Los Angeles.