Geology


Los Angeles is subject to earthquakes due to its location in the Pacific Ring of Fire. The geologic instability produces numerous fault lines both above and below ground, which altogether cause approximately 10,000 earthquakes every year. One of the major fault lines is the San Andreas Fault. Located at the boundary between the Pacific Plate and the North American Plate, it is predicted to be the source of Southern California's next big earthquake. Major earthquakes to have hit the Los Angeles area include the 1994 Northridge earthquake, the 1987 Whittier Narrows earthquake, the 1971 San Fernando earthquake near Sylmar, and the 1933 Long Beach earthquake. Nevertheless, all but a few quakes are of low intensity and are not felt The most recent earthquake felt was the 4.7 2009 Inglewood earthquake on May 17, 2009. Parts of the city are also vulnerable to Pacific Ocean tsunamis; harbor areas were damaged by waves from the Valdivia earthquake in 1960. The Los Angeles basin and metropolitan area are also at risk from blind thrust earthquakes