Richter scale

American  

noun

1. a scale, ranging from 1 to 10, for indicating the intensity of an earthquake.

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Richter scale British  

/ ˈrɪxtə /

noun

1. a scale for expressing the magnitude of an earthquake in terms of the logarithm of the amplitude of the ground wave; values range from 0 to over 9 Compare Mercalli scale See also magnitude

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Richter scale Scientific  

/ rĭk′tər /

1. 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).

2. See Note at earthquake

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Richter scale Cultural  

1. A scale used to rate the intensity of earthquakes. The scale is open-ended, with each succeeding level representing ten times as much energy as the last. A serious earthquake might rate six to eight, and very destructive quakes rate higher.

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Discover More

No quake greater than nine has ever been recorded.

Etymology

Origin of Richter scale

1935–40; after Charles F. Richter (1900–85), U.S. seismologist

Compare meaning

How does richter-scale compare to similar and commonly confused words? Explore the most common comparisons:

• Mercalli scale vs. Richter scale

Example Sentences

Typically, one earthquake per year reaches a magnitude of 8.0 or higher, while around 15 others fall within the magnitude 7 range on the Richter scale, which measures the amount of energy released.

From Science Daily • Jan. 6, 2026

Sunday's quake was preceded by three smaller ones of more than 4.0 magnitude, while the three on Monday morning were also more than 4.0 on the Richter scale.

From BBC • Feb. 10, 2025

And their resulting roar might have registered on the Richter scale.

From Los Angeles Times • Oct. 29, 2024

This is true for most onshore locations impacted by the 1964 earthquake, which hit 9.2 on the Richter scale.

From Science Daily • May 20, 2024

Aunt Gloria looked at Marcus with an expression that was off the Richter scale.

From "The London Eye Mystery" by Siobhan Dowd