Geological Survey Program
Relationship of Increasing Magnitudes
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The Richter magnitude scale is commonly used but often misunderstood
Each whole-number step of magnitude represents a tenfold increase in amplitude. Therefore, the amplitude of an 8.3-magnitude earthquake is not twice that of a magnitude 4.3 quake but rather 10,000 times as large.
The volumes of the spheres shown here are scaled to illustrate the relative increase in magnitude. At this scale, magnitudes of 1, 2, 3 and 4 would be roughly proportional to a small marble, a golf ball, a grapefruit and a basketball.
At the same time, the energy released by an earthquake of magnitude 8.7 could be represented by the sphere the size of a hot-air balloon.
- The New Madrid Seismic Zone
- Facts About New Madrid Seismic Zone
- Earthquake Occurrences in Southeast Missouri
- History of Earthquakes in Missouri
- Understanding Earthquakes
- Measuring Earthquakes
- Relationship of Increasing Magnitudes
- Relationship Between Richter Magnitude and Modified Mercalli Intensity
- Recent Earthquakes in Central US
- What to do before, during and after an earthquake
- Earthquake Hazard in the New Madrid Seismic Zone Remains a Concern
- Earthquake Scenario -- 2011 Exercise
- Eyewitness Accounts of the 1811-12 New Madrid Earthquakes
- Seismographs in Missouri -- The USArray Transportable Array
- Earthquake Info -- News articles (searchable) compiled by the Central United States Earthquake Consortium
- Did you feel it?
- Missouri Seismic Safety Commission
- Additional Links