Modified Mercalli Scale Close this window

I. Not felt.
II. Felt by persons at rest, on upper floors, or favorably placed.
III. Felt indoors. Hanging objects swing. Vibration like passing of light trucks.
IV. Hanging objects swing. Windows, doors, dishes rattle. Vibration like passing of heavy truck or jolt like a heavy ball striking the walls.
V. Felt outdoors, sleepers wakened. Liquids disturbed or spilled. Small unstable objects displaced or upset. Pictures move.
VI. Felt by all. Persons walk unsteadily. Windows dishes and glasses broken. Pictures off walls. Furniture moved or overturned. Weak plaster and masonry cracked.
VII. Difficult to stand. Noticed by car drivers. Furniture broken. Damage to weak masonry, some cracks in ordinary masonry. Weak chimneys broken at roof line. Fall of plaster, loose bricks, stones, tiles and unbraced parapets.
VIII. Steering of cars affected. Damage to ordinary masonry, partial collapse. Twisting, fall of chimneys, factory stacks, monuments, towers, elevated tanks. Frame houses moved on foundations if not bolted down; loose panel walls thrown out. Cracks in wet ground and on steep slopes.
IX. General Panic. Poor masonry destroyed, ordinary masonry heavily damaged, sometimes with complete collapse, reinforced masonry damaged, general damage to foundations. Frame structures, if not bolted, shifted off foundations. Frames racked. Underground pipes broken. Conspicuous cracks in ground. Liquefaction in areas of sand and mud.
X. Most masonry and frame structures destroyed. Some well-built wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large landslides. Rails bent slightly.
XI. Rails bent greatly. Underground pipelines completely out of service.
XII. Damage nearly total. Large rock masses displaced.