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The Richter Scale

A variety of methods have been devised for expressing the magnitude, or intensity, of earth movements. For many years, the most popular of these has been the Richter scale, named after seismologist Charles F. Richter, who developed the scale in 1935. The Richter scale is logarithmic. That is, each increase of one unit on the scale represents an increase of ten in the intensity of the earth movement measured. An earthquake that measures 6.0 on the Richter scale, as an example, is ten times as intense as one that measures 5.0 and one hundred times as intense as one that measures 4.0.

See also Earth's interior.



Richter, C.F. Elementary Seismology. San Francisco: W. H. Freeman, 1958.

Scholz, C. H. The Mechanics of Earthquakes and Faulting. New York: Cambridge University Press, 1990.


Grollimund, B., and M.D. Zoback. "Did Deglaciation Trigger Intraplate Seismicity in the New Madrid Seismic Zone?" Geology 29, 2 (February 2001):175-178.

David E. Newton


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—The tendency of an object in motion to remain in motion, and the tendency of an object at rest to remain at rest.


—A device consisting of a weight hung from a support system so that the weight can swing back and forth as a result of the Earth's gravitational field.


—A component of a seismograph that detects earth movements.


—A primitive type of seismograph that was capable of detecting movements in the Earth's surface, but that did not record those movements.

Additional topics

Science EncyclopediaScience & Philosophy: Jean-Paul Sartre Biography to Seminiferous tubulesSeismograph - Type Of Seismometers, Recording Systems, Practical Considerations, The Richter Scale - The modern seismograph