| Mercalli Intensity (at epicenter) | Magnitude | Witness Observations |
| I | 1 to 2 | Felt by very few people; barely noticeable. |
| II | 2 to 3 | Felt by a few people, especially on upper floors. |
| III | 3 to 4 | Noticeable indoors, especially on upper floors, but may not be recognized as an earthquake. |
| IV | 4 | Felt by many indoors, few outdoors. May feel like heavy truck passing by. |
| V | 4 to 5 | Felt by almost everyone, some people awakened. Small objects moved. Trees and poles may shake. |
| VI | 5 to 6 | Felt by everyone. Difficult to stand. Some heavy furniture moved, some plaster falls. Chimneys may be slightly damaged. |
| VII | 6 | Slight to moderate damage in well built, ordinary structures. Considerable damage to poorly built structures. Some walls may fall. |
| VIII | 6 to 7 | Little damage in specially built structures. Considerable damage to ordinary buildings, severe damage to poorly built structures. Some walls collapse. |
| IX | 7 | Considerable damage to specially built structures, buildings shifted off foundations. Ground cracked noticeably. Wholesale destruction. Landslides. |
| X | 7 to 8 | Most masonry and frame structures and their foundations destroyed. Ground badly cracked. Landslides. Wholesale destruction. |
| XI | 8 | Total damage. Few, if any, structures standing. Bridges destroyed. Wide cracks in ground. Waves seen on ground. |
| XII | 8 or greater | Total damage. Waves seen on ground. Objects thrown up into air. |