The Northridge earthquake occurred at 4:30am on January 17, 1994. Northridge is located approximately 30km northwest of Los Angeles. This earthquake had a 6.9 moment magnitude with a duration of 10-20 seconds. The earthquake occurred along a "blind" thrust fault (it is buried), close to San Andreas fault.
The earthquake was caused mainly by a previously undiscovered strike-slip fault in Reseda.
The number of fatalities in the Northridge earthquake was about 57. About 9000 people were injured. The fact that the earthquake occured at 4:30am lessened the death toll.
The Northridge earthquake caused extensive damage to parking structures and freeway overpasses. A 2500 car parking garage at the California State University at Northridge collapsed. The earthquake caused and triggered landslides in the Santa Susana Mountains, Santa Monica Mountains, and wetsern San Gabriel Mountains. These landslides blocked roads and damaged water linesa as well as damaging homes. Because Northridge area has arid, dry soil thus having few liquefaction and ground failure effects. There were, although, damage due to fires. Estimates of total damage range between $13-40 billion.
The Northridge earthquake caused extensive damage to parking structures and freeway overpasses. A 2500 car parking garage at the California State University at Northridge collapsed. The earthquake caused and triggered landslides in the Santa Susana Mountains, Santa Monica Mountains, and wetsern San Gabriel Mountains. These landslides blocked roads and damaged water linesa as well as damaging homes. Because Northridge area has arid, dry soil thus having few liquefaction and ground failure effects. There were, although, damage due to fires. Estimates of total damage range between $13-40 billion.
The Universal Studios attraction had shut down during this time as well as Disneyland, Knott's Berry Farm, and Six Flags; all very popular attractions.
A respiratory disease called the Valley fever outbreak occurred 8 weeks following the earthquake. It is believed that the spores were carried in large clouds of dust created by seismically triggered landslides.
The Northridge earthquake led to a number of legislative changes. Due to the large amount lost by insurance companies because of the earthquake, most insurance companies either stopped offering or severely restricted earthquake insurance in California. In response, the California Legislature created the California Earthquake Authority (CEA), which is a publicly managed but privately funded organization that offers minimal coverage. A substantial effort was also made to reinforce freeway bridges against seismic shaking, and a law requiring water heaters to be properly strapped was passed in 1995.
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