Richter scale science definition

A logarithmic scale used to rate the strength or total energy of earthquakes. The scale has no upper limit but usually ranges from 1 to 9. Because it is logarithmic, an earthquake rated as 5 is ten times as powerful as one rated as 4. An earthquake with a magnitude of 1 is detectable only by seismographs; one with a magnitude of 7 is a major earthquake. The Richter scale is named after the American seismologist Charles Francis Richter (1900-1985). See Note at earthquake.