The Canadian Encyclopedia — neutral, cited, updated
July 26, 2026Sources cited
Canadianwire.
Canada’s encyclopedia & explainer
Home›Science & Nature›Geology›Richter scale
Science & Nature • Geology

Richter scale

The Richter scale is a logarithmic scale used to measure earthquake magnitude from seismogram amplitude data.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

The Richter scale is a logarithmic scale used to measure earthquake magnitude from seismogram amplitude data. It was developed in 1935 by Charles F. Richter, with Beno Gutenberg, and is now largely replaced in routine use by the moment magnitude scale for large earthquakes. The scale is commonly associated with local earthquake magnitude and is still widely recognized in public language.

Definition

The Richter scale is a seismological magnitude scale used to express the size of an earthquake from measured ground-motion amplitudes. It is commonly associated with local earthquake magnitude.

History

Charles F. Richter developed the scale in 1935 with Beno Gutenberg at the California Institute of Technology. The scale was designed to compare the sizes of earthquakes using instrument readings.

How it works

Because it is logarithmic, an increase of one unit means a tenfold increase in measured amplitude and a much larger increase in energy release. The original calculation depended on seismograph amplitude and the distance from the earthquake source.

Use in modern seismology

The Richter scale is still widely recognized in public language, but seismologists generally use moment magnitude for larger earthquakes because it is more accurate across a wider range of events.

Key facts

  • The Richter scale is a magnitude scale for earthquakes, not a measure of damage.
  • It is logarithmic: each whole-number increase corresponds to a tenfold increase in wave amplitude.
  • It was introduced in 1935 by Charles F. Richter and Beno Gutenberg.
  • The original method used Wood-Anderson seismograph recordings at relatively short distances from the epicentre.
  • The scale has no strict theoretical upper limit, although the largest recorded earthquakes are below magnitude 10.
🍁
Canadian context

Canadian seismologists and emergency agencies use earthquake magnitude concepts in public reporting, especially for earthquakes in British Columbia, the Yukon, and eastern Canada. The term "Richter scale" is still widely understood by Canadian readers, although modern scientific reporting usually uses moment magnitude.

Frequently asked questions

What does the Richter scale measure?
It measures earthquake magnitude, based on the amplitude of seismic waves recorded on instruments.
Is the Richter scale logarithmic?
Yes. Each increase of one unit represents a tenfold increase in wave amplitude.
Who created the Richter scale?
It was developed by Charles F. Richter in collaboration with Beno Gutenberg.
Is the Richter scale still used?
The term remains common in public usage, but moment magnitude is now preferred for larger earthquakes.
Does the Richter scale measure damage?
No. Earthquake damage depends on many factors, including depth, distance, building strength, and local ground conditions.

References

  1. Wikipedia — https://en.wikipedia.org/wiki/Richter_scale
    Supports: Developed by Charles Richter with Beno Gutenberg; alternate names; historical introduction in 1935.
  2. Wikipedia — https://de.wikipedia.org/wiki/Richterskala
    Supports: Magnitude scale for earthquakes; based on amplitude measurements; local earthquake magnitude usage.
  3. Britannica — https://www.britannica.com/summary/Richter-scale
    Supports: Logarithmic nature; 10-fold amplitude increase per unit; original developers; modern replacement by moment magnitude for large earthquakes.