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 |