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 Another type of scale called the Richter scale is a mathematical measurement of the energy released as measured by a seismograph. It is actually a measurement of the size of the waves produced by an earthquake. The Richter Scale, was developed by Charles F. Richter of the California Institute of Technology in 1935. This scale is the best known scale for the measuring of magnitude (M) of earthquakes. The scale is logarithmic. A magnitude 7, for example, records a disturbance with ground motion 10 times as large as a recording of 6 magnitude earthquake. The energy released by an earthquake of M 7,however, is approximately 30 times that released by an earthquake of M 6. An earthquake of M 8 releases 900 times (30x30) the energy of an earthquake of M 6. There is only one "magnitude" for an earthquake using the Richter scale. As the Richter scale does not adequately differentiate between the largest earthquakes, a new "moment magnitude" scale is being used by seismologists today to provide a better measure. On the moment magnitude scale, the San Francisco earthquake is estimated at magnitude 7.7 compared to an estimated Richter magnitude of 8.3. Charles F.Richter
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