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Earthquake Scales
The Info Service Chart & Reference Guide
| Moment Magnitude |
Richter Magnitude |
Mercalli Intensity |
Description |
| 1.0-3.0 | 2 | I | Usually not felt, detected by instruments. |
| 3.0 | 2 | II | Felt by few, especially on upper floors of buildings, detected by instruments. |
| 3.9 | 3 | III | Felt noticeably indoors, vibration like a passing vehicle, cars may rock. |
| 4.0 | n/a | IV | Felt indoors by many, outdoors by few, dishes & windows broken, some cracked plaster, trees disturbed. |
| 4.9 | 4 | V | Felt by most people, slight damage; some dishes & windows broken, some cracked plaster, trees disturbed. |
| 5 | 5 | VI | Felt by all, many frightened and run outdoors, damage minor to moderate. |
| 5.9 | 5 to 6 | VII | Everyone runs outdoors, much damage to poor design buildings, minor damage to good design buildings, some chimneys broken, noticed by people driving cars. |
| 6 | 6 | VIII | Everyone runs outdoors, damage is moderate to major. Damage minor in well designed structures, major in poor designs; chimneys, columns & walls fall, heavy furniture turned, well water changes; sand & mud ejected. |
| 6.9 | 7 | IX | Major damage in all structures, ground cracked, pipes broken, shift foundation. |
| 7.0+ | 7 & 8 | X | Major damage, most masonry & frame structures destroyed, ground badly cracked, landslides, water sloshed over river banks, rails bent. |
| n/a | 8 | XI | Almost all masonry structures destroyed, bridges fall, big fissures in ground, land slumps, rails bent greatly. |
| n/a | 8 & above | XII | Total destruction. Ground surface waves seen, objects thrown up into the air. All construction destroyed. |