what is the scale used to measure earthquakes

The scale most people know for measuring earthquakes is the Richter scale , but today scientists mainly use the moment magnitude scale (Mw) , which is similar in concept but more accurate for large quakes.

Quick Scoop: What is the scale used to measure earthquakes?

1. Short, direct answer

• Earthquake magnitude (how much energy is released) is measured using seismic magnitude scales.
• Historically, this was the Richter scale (local magnitude, ML) , but modern seismology usually uses the moment magnitude scale (Mw) , even though news reports still often call it “Richter.”

2. Richter scale in a nutshell

• Developed in 1935 by Charles Richter and Beno Gutenberg to compare earthquake sizes in California.

• It uses the logarithm of the amplitude of seismic waves recorded by a seismograph: each step of 1.0 in magnitude means 10 times larger wave amplitude and about 31 times more energy released.

• It works best for small to moderate, nearby earthquakes and starts to become inaccurate for very big or distant ones.

Think of it like an old but famous “rating system” that everyone knows, even though professionals now use a newer, better one in the background.

3. Moment magnitude scale (Mw): what experts actually use

• The moment magnitude scale (Mw) is now the standard global scale used by seismologists and agencies like USGS for reporting earthquake size.

• Instead of just wave height at one instrument, it is based on the total seismic moment :
  • how big the fault area is,
  • how far it slipped,
  • and the force needed to move it.

• It gives reliable values for small and very large earthquakes , so a magnitude 7 or 9 you see in recent “latest news” reports is almost always Mw , even if it’s described in media as “on the Richter scale.”

4. Other useful scales (intensity vs magnitude)

There’s also a different way to “measure” an earthquake: how strongly people feel it and how much damage it does in a specific place.

• This is called intensity , not magnitude.
• A common scale is the Modified Mercalli Intensity (MMI) scale, which runs from “not felt” to “extreme destruction.”

• One single earthquake has one magnitude , but many intensities depending on distance, depth, and local ground conditions.

5. Mini FAQ

Q: So what should I say in an exam or interview?

• Typical safe answer:
  • “Earthquakes are measured using seismic magnitude scales , most famously the Richter scale , but today scientists mainly use the moment magnitude scale (Mw).”

Q: Why are people still talking about the Richter scale in 2026?

• It became a popular term in the mid–20th century, so media and public usage lag behind scientific practice, even though experts shifted to Mw for large global quakes.

TL;DR:
The classic Richter scale is the famous name, but modern earthquake measurements mostly use the moment magnitude scale (Mw) to report how strong an earthquake is.

Information gathered from public forums or data available on the internet and portrayed here.