The moment magnitude scale is a way to measure the power of earthquakes. It is the energy of the earthquake at the moment it happens. Like the similar and older Richter scale, it is logarithmic, with a base of ten. This means that an earthquake with a magnitude of 2 is ten times stronger than an earthquake with a magnitude of 1.
| Scale Number | Earthquake Effect |
|---|---|
| less than 3.5 | This would be a very weak earthquake. People would not feel it, but it would be recorded by geologists. |
| 3.5-5.4 | Generally felt by people, but it rarely causes damage. |
| 5.4-6.0 | Will not cause damage to well-designed buildings, but can cause damage or destroy small or poorly-designed ones. |
| 6.1-6.9 | Can be destructive in areas up to about 100 kilometers across where people live. |
| 7.0-7.9 | Considered a "major earthquake" that causes a lot of damage. |
| 8 or greater | Large and destructive earthquake that can destroy large cities. |