Quantcast
Earthquake measure seismograph magnitude | The Old Farmer's Almanac

How to Measure Earthquakes

Primary Image
No content available.
Print Friendly and PDF
Body

Wondering how earthquakes are measured? Seismologists have developed a new measurement of earthquake size, called the Moment Magnitude.

All earthquakes can now be compared on the same scale with the Moment Magnitude. Previously, the Richter scale was used, however, it is precise only for measuring earthquakes of a certain size and at a certain distance from a seismometer.

See the Moment Magnitude chart below.

Magnitude Effect
Less than 3 Micro
3–3.9 Minor
4–4.9 Light
5–5.9 Moderate
6–6.9 Strong
7–7.9 Major
8 or more Great