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Richter Magnitude Scale
The Richter Magnitude Scale, more commonly used by the media and the public, measures
the magnitude of the
earthquake. It is calculated logarithmically in which each
unit of amplitude of earthquake waves is factored ten times
larger than the previous
reading. An earthquake measured at 8.0, for example, would be 10,000 times stronger
than
an earthquake measured at 4.0.
How is the Richter Magnitude of an Earthquake Arrived At?
Calculate the logarithm to base ten of the maximum seismic-wave amplitude (in 1000ths
of a milimeter) recorded
on a standard seismograph at a distance of 100 kilometers from
the earthquake center. Got that?
| Magnitude Under 2 |
"Micro
Quake" - Recorded on local seismographs. Generally not felt. |
| Magnitude 3 |
Normally
not felt. |
| Magnitude 4 |
Often
felt. Damage is rare. |
| Magnitude 5 |
Felt widely.
Normally only slight damage. |
| Magnitude 6 |
Poorly constructed
buildings are damaged. |
| Magnitude 7 - 7.8 |
Very serious damage
occurs. |
| Magnitude 7.8+ |
"Great
Quake" - Tremendous destruction and loss of life. |
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