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

Intensity Scale Description
I

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

II

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

III

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

 IV

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

V

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

 VI

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.

 VII

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.

 VIII

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.

IX

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