Historic Earthquakes of California

Listed below are the major historic earthquakes with a magnitude of 6 or greater that have hit California prior to the year 2000. The top ten earthquakes of California are highlighted in dark yellow, and their ranking given in blue. Some honorable mentions are highlighted in light yellow.

The above table from 1769 to 2004 is based on "California Earthquake History 1769-present", which is a list put together by the United States Geological Survey (USGS). Updates on recent earthquakes from 2005 to the present are based on entries in Wikipedia. The magnitudes that the USGS gives for earthquakes after 1898 are similar to the famous Richter scale, in which the magnitude, more or less, represents the energy of the earthquake. This value is calculated from the distance that the needle on a seismograph moves during an earthquake. Thus, it depends on the amplitude of the surface wave associated with the quake. Because seismographs were not available prior to 1898, the magnitudes of earthquakes prior to then must be estimated from the intensity of damage associated with the quake as reported by witnesses to the event. The links below give more information.

Richter Scale     Mercalli Intensity

Listed below are the top ten earthquakes to have hit California in historic times. Again the sizes of earlier quakes are estimates, and they will differ depending on which authority is being consulted. For example, some scientists believe that the 1857 Tejon earthquake was the largest to hit California in historic times, and other experts rank the San Francisco Earthquake of 1906 as the larger of the two.