The following is a top ten list of the largest earthquakes ever recorded in history by magnitude. While there have been a large number of earthquakes that have measured a magnitude of between 8 and 9, there are only six on record that have measured between 9 and 10.
http://www.sciencekids.co.nz/sciencefacts/topten/largestearthquakes.html
The World’s largest earthquake with an instrumentally documented magnitude occurred on May 22, 1960 near Valdivia, in southern Chile. It was assigned a magnitude of 9.5 by the United States Geological Survey. It is referred to as the Great Chilean Earthquake and the 1960 Valdivia Earthquake.
http://geology.com/records/largest-earthquake/
Largest Earthquakes in History. The following is a top ten list of the largest earthquakes ever recorded in history by magnitude. While there have been a large number of earthquakes that have measured a magnitude of between 8 and 9, there are only six on record that have measured between 9 and 10.
http://www.sciencekids.co.nz/sciencefacts/topten/largestearthquakes.html
The following table lists the largest earthquakes in the United States on record, according to rank, magnitude, date, and location. The largest earthquake to hit the U.S. was on March 28, 1964, when a 9.2 magnitude quake struck Prince William Sound in Alaska.
http://www.infoplease.com/ipa/A0193595.html
The Largest Earthquakes in the United States. The following table lists the largest earthquakes in the United States on record, according to rank, magnitude, date, and location. The largest earthquake to hit the U.S. was on March 28, 1964, when a 9.2 magnitude quake struck Prince William Sound in Alaska.
http://www.infoplease.com/ipa/A0193595.html
Other earthquakes in recorded history may have been larger, however this is the largest earthquake that has occurred since accurate estimates of magnitude became possible in the earnly 1900's. The earthquake occurred beneath the Pacific Ocean off the coast of Chile.
http://geology.com/records/largest-earthquake/
The extensive records of the United States Geological Service (USGS) show that the biggest earthquake since 1900 occurred near the cities of Valdivia and Puerto Montt, Chile, in 1960. Known as the Great Chilean Earthquake, the quake measured 9.5 on the Richter scale.
http://www.wisegeek.org/what-is-the-biggest-earthquake-ever-recorded.htm
In the 1970s, the moment magnitude scale was introduced to describe the physical size of an earthquake, and is preferred for very large earthquakes. Here are the biggest earthquakes in California's recorded history, according to magnitude estimates from the U.S Geological Survey.
http://news.nationalgeographic.com/news/2014/08/140825-earthquake-california-biggest-magnitude-history/
The largest earthquake ever recorded was in Chile in 1960 and it was recorded at a magnitude 9.5. It is said that 1,655 people were found dead and over 3,000 were injured. Two million citizens of Chile were left homeless after this natural disaster.
http://www.curiosityaroused.com/nature/the-top-10-largest-earthquakes-ever-recorded/
Sunday's shake-up was one of the largest to strike northern California since the magnitude 6.9 Loma Prieta quake in 1989. But quakes of magnitude 6.0 and greater are not uncommon historically along California's network of faults, notably the San Andreas.
http://news.nationalgeographic.com/news/2014/08/140825-earthquake-california-biggest-magnitude-history/
what is califorinas largest earthquakes ever recorded
The largest earthquake ever recorded in California is Loma Prieta quake in 1989. The  Califorinas largest earthquakes ever recorded is of Magnitude 6.9 Loma Prieta quake in 1989. In California, the 1989 Loma Prieta earthquake with magnitude 6.9 is the largest earthquake ever recorded.