Intensity

Description

Characteristics

I

Not felt

1. Not felt even under the most favourable circumstances
2. No effect
3. No damage

II

Scarcely felt

1. The tremor is felt only by a very few [<1%] individuals at rest and in a specially receptive position indoors
2. No effect
3. No damage

III

Weak

1. The earthquake is felt indoors by a few. People at rest feel a swaying or a light trembling
2. Hanging objects swing slightly
3. No damage

IV

Largely observed

1. The earthquake is felt indoors by many and felt outdoors only by a very few. A few people are awakened. The level of vibration is not frightening. The vibration is moderate. Observers feel a slight trembling or swaying of the building, room or bed, chair etc.
2. China, glasses, windows and doors rattle. Hanging objects swing. Light furniture shakes visibly in a few cases. Woodwork creaks in a few cases.
3. No damage

V

Strong

1. The earthquake is felt indoors by most, outdoors by few. A few people are frightened and run outdoors. Many sleeping people awake. Observers feel a strong shaking or rocking of the whole building, room or furniture.
2. Hanging objects swing considerably. China and glasses clatter together. Small, top-heavy and/or precariously supported objects may be shifted or fall down. Doors and windows swing open or shut. In a few cases window panes break. Liquids oscillate and may spill from well-filled containers. Animals indoors may become uneasy.
3. Damage of grade 1 to a few buildings

VI

Slightly damaging

1. Felt by most indoors and many outdoors. A few persons lose their balance. Many people are frightened and run outdoors.
2. Small objects of ordinary stability may fall and furniture may be shifted. In few instances dishes and glassware may break. Farm animals [even outdoors] may be frightened.
3. Damage of grade 1 is sustained by many buildings; a few suffer damage of grade 2.

VII

Damaging

1. Most people are frightened and run outdoors. Many find it difficult to stand, especially on upper floors.
2. Furniture is shifted and top-heavy furniture may be overturned. Objects fall from shelves in large numbers. Water splashes from containers, tanks and pools.
3. Many buildings of vulnerability class B and a few of class C suffer damage of grade 2. Many buildings of class A and a few of class B suffer damage of grade 3; a few buildings of class A suffer damage of grade 4. Damage is particularly noticeable in the upper parts of buildings.

VIII

Heavily damaging

1. Many people find it difficult to stand, even outdoors.
2. Furniture may be overturned. Objects like TV sets, typewriters etc. fall to the ground. Tombstones may occasionally be displaced, twisted or overturned. Waves may be seen on very soft ground.
3. Many buildings of vulnerability class C suffer damage of grade 2. Many buildings of class B and a few of class C suffer damage of grade 3. Many buildings of class A and a few of class B suffer damage of grade 4; a few buildings of class A suffer damage of grade 5. A few buildings of class D suffer damage of grade 2.

IX

Destructive

1. General panic. People may be forcibly thrown to the ground.
2. Many monuments and columns fall or are twisted. Waves are seen on soft ground.
3. Many buildings of vulnerability class C suffer damage of grade 3. Many buildings of class B and a few of class C suffer damage of grade 4. Many buildings of class A and a few of class B suffer damage of grade 5. Many buildings of class D suffer damage of grade 2; a few suffer grade 3. A few buildings of class E suffer damage of grade 2.

X

Very destructive

1. Many buildings of vulnerability class C suffer damage of grade 4. Many buildings of class B and a few of class C suffer damage of grade 5, as do most buildings of class A. Many buildings of class D suffer damage of grade 3; a few suffer grade 4. Many buildings of class E suffer damage of grade 2. A few suffer grade 3. A few buildings of class F suffer damage of grade 2.

XI

Devastating

1. Most buildings of vulnerability class C suffer damage of grade 4. Most buildings of class B and many of class C suffer damage of grade 5. Many buildings of class D suffer damage of grade 4; a few suffer grade 5. Many buildings of class E suffer damage of grade 3. A few suffer grade 4. Many buildings of class F suffer damage of grade 2, a few suffer grade 3.

XII

Completely devastating

1. Practically all structures above and below ground are destroyed.

Grade

Masonry Buildings

Reinforced Concrete Buildings

1: Negligible to slight damage [no structural damage]

Hairline cracks in very few walls; fall of small pieces of plaster only. Fall of loose stones from upper parts of buildings in very few cases only

Fine cracks in plaster over frame members and in partitions.

2: Moderate damage [slight structural damage, moderate non-structural damage]

Cracks in many walls; fall of fairly large pieces of plaster; parts of chimneys fall down.

Hairline cracks in columns and beams; mortar falls from the joints of suspended wall panels; cracks in partition walls; fall of pieces of brittle cladding and plaster.

3: Substantial to heavy damage [moderate structural damage, heavy non-structural damage]

Large and extensive cracks in most walls; pantiles or slates slip off. Chimneys are broken at the roof line; failure of individual non-structural elements

Cracks in columns with detachment of pieces of concrete, cracks in beams.

4: Very heavy damage [heavy structural damage, very heavy non-structural damage]

Serious failure of walls; partial structural failure.

Severe damage to the joints of the building skeleton with destruction of concrete and protrusion of reinforcing rods; partial collapse; tilting of columns.

5: Destruction [very heavy structural damage]

Total or near total collapse.

Total or near total collapse.