Earthquake Facts and Statistics
Frequency of Occurrence of Earthquakes
| Magnitude | Average Annually |
|---|---|
| 8 and higher | 1 ¹ |
| 7 - 7.9 | 15 ¹ |
| 6 - 6.9 | 134 ² |
| 5 - 5.9 | 1319 ² |
| 4 - 4.9 | 13,000 (estimated) |
| 3 - 3.9 | 130,000 (estimated) |
| 2 - 2.9 | 1,300,000 (estimated) |
Magnitude vs. Ground Motion and Energy
| Magnitude Change | Ground Motion Change (Displacement) | Energy Change |
|---|---|---|
| 1.0 | 10.0 times | about 32 times |
| 0.5 | 3.2 times | about 5.5 times |
| 0.3 | 2.0 times | about 3 times |
| 0.1 | 1.3 times | about 1.4 times |
As more and more seismographs are installed in the world, more earthquakes can be and have been located. However, the number of large earthquakes (magnitude 6.0 and greater) has stayed relatively constant.