How often do severe earthquakes occur on...

The states of California, with its infamous San Andreas Fault, and Nevada experience the most earthquakes. More than 300,000 earthquakes have been recorded in these two states since 1836, including 10 of the 15 largest earthquakes in the contiguous United States. The largest earthquake in California and the second largest in the United States registered 7.9 on the Richter scale and occurred along the San Andreas Fault in Fort Tejon in 1857. One person was killed, and the earthquake caused significant property damage. Here are some more recent examples of severe earthquakes in that area: A 1933 quake in Long Beach, California, registered 6.3, killed 115 people, and caused $40 million in damage. A 1952 quake in Kern County registered 6.1, killed 12 people, and caused $60 million in damage. The 1971 San Fernando quake registered 6.5, killed 65 people, injured more than 2,000, and caused $505 million in damage, including the destruction of new, supposedly earthquake-resistant buildings at the Olive View Hospital in Sylmar. The famous Loma Prieta quake of 1989—watched by many during the World Series—registered 7.1, killed 63 people, injured more than 3,700, and caused $6 billion in damage. The Northridge quake of 1994, which happened in a densely populated area of Los Angeles, registered 6.8, killed 57 people, seriously injured more than 1,500, and resulted in $20 billion in damage, including several important Los Angeles freeways. For many days after the earthquake, thousands of homes were without gas and electricity, and 49,000 homes had no water, making this one of the biggest earthquakes in terms of disruption of life.