 Complete the following phrase:  Los Angeles is subject to earthquakes because of its location on the Pacific Ring of Fire. The geologic instability has produced numerous faults, which cause approximately 10,000 earthquakes annually in Southern California, though most of them are too small to be felt. The strike-slip San Andreas Fault system, which sits at the boundary between the Pacific Plate and the North American Plate, passes through the Los Angeles metropolitan area. The segment of the fault passing through Southern California experiences a major earthquake roughly every 110 to 140 years, and seismologists have warned about the next big one, as the last major earthquake was the 1857 Fort Tejon earthquake. The Los Angeles basin and metropolitan area are also at risk from blind thrust earthquakes. Major earthquakes that have hit the Los Angeles area include the 