# What is the Moment Magnitude Scale?

08-02-2023

1 min read

### Overview:

#### An extremely large earthquake with a magnitude 7.8 out of 10 on the moment magnitude scale occurred in the southeast of Turkey, near the border with Syria.

## About Moment Magnitude Scale:

- It is a
**logarithmic scale that measures the total amount of energy**released by**an earthquake.**

- It is the
**only scale capable of**reliably**measuring**the magnitudes of the largest,**most destructive earthquakes**(that is, greater than magnitude 8). - It was
**developed in the 1970s**by Japanese seismologist**Hiroo Kanamori**and American seismologist**Thomas C. Hanks.** **How is it calculated?**

- The moment magnitude scale is
**based on the total moment release of the earthquake.** **Moment is a product of the distance a fault moved**and the**force required to move it.****It is derived from modeling recordings**of the earthquake at multiple stations.**Moment magnitude estimates are about the same as Richter magnitudes**for small to large earthquakes. But only the moment magnitude scale is**capable of measuring M8**(read "magnitude 8") and**greater events accurately.**

### What is the Richter scale?

- It was
**invented in 1935 by Charles F. Richter**as a mathematical device**to compare the size of earthquakes.** - The Richter scale is
**used to rate the magnitude of an earthquake**, that is, the**amount of energy released during an earthquake.** - The Richter scale is a
**base-10 logarithmic scale**, meaning**each order**of magnitude is**10 times more intensive than the last one.** - It is
**most effective**for regional earthquakes**no greater than magnitude 5.** **How is it calculated?**

- The Richter scale involves measuring the
**amplitude (height) of the largest recorded wave at a specific distance from the seismic source.** **Adjustments are included for the variation in the distance**between the various seismographs and the epicenter of the earthquakes.- The Richter scale
**doesn't measure quake damage.**

### Q1) What is a logarithmic scale?

A logarithmic scale is a nonlinear scale often used when analyzing a large range of quantities. Instead of increasing in equal increments, each interval is increased by a factor of the base of the logarithm. Typically, a base ten and base e scale are used.

**Source: **Turkey-Syria Earthquakes: A Seismologist Explains What Happened