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Rossi-Forrel Scale of Earthquake Intensities (Adapted) PDF Print
Friday, 09 May 2008 19:36


Intensity Scale Description

Hardly perceptible shock - felt only by an experienced observer under favorable conditions.


Extremely feeble shock - felt by a small number of persons at rest.


Very feeble shock - felt by several persons at rest. Duration and direction may be perceptible. Sometimes dizziness or nausea experienced.


Feeble shock - felt generally indoors, outdoors by a few. Hanging objects swing slightly. Creaking of frames of houses.


Shock of moderate intensity - felt generally by everyone. Hanging objects swing freely. Overturning of tall vases and unstable objects.


Fairly strong shock - general awakening of those asleep. Some frightened persons leave their houses. Stopping of pendulum clocks. Oscillation of hanging lamps. Slight damage to very old or poorly built structures.


Strong shock - overturning of movable objects. General alarm, all run outdoors. Damage slight in well-built houses, considerable in old or poorly built structures, old walls, etc. Some landslides from hills and steep banks. Cracks in road surfaces.


Very strong shock - people panicky. Trees shaken strongly. Changes in the flow of springs and wells. Sand and mud ejected from fissures in soft ground. Small landslides.


Extremely strong shock - panic general. Partial or total destruction of some buildings. Fissures in ground. Landslides and rockfalls.