Book 12, Question 28
How Do We Measure How Strong an Earthquake Is?
Earthquake strength is measured with a number called magnitude. The scale most scientists use today is called moment magnitude. It replaced the older Richter scale, which worked best for medium quakes.
More fun facts
- The famous Richter scale measures the biggest wiggle on a seismograph recording.
- The US Geological Survey no longer uses the Richter scale for large earthquakes.
- The moment magnitude scale measures an earthquake's size at its source and is more accurate.
- Different magnitude scales measure different parts of an earthquake.
- Magnitude, energy release and shaking intensity are related measurements that people often mix up.
Sources: U.S. Geological Survey, U.S. Geological Survey, BBC
Questions kids ask
Is the Richter scale still used?
Many people still say it, but scientists mostly use moment magnitude for big quakes.