JMA seismic intensity scale

Reference items

Scale

Explanation

0

No feeling. Shocks too weak to be felt by humans, registered only by seismographs.

Not felt unless shaking is felt by the body, even when a hanging object is seen to be slightly swinging or some rattling is heard.

I

Slight. Extremely weak shocks felt only by persons at rest or by those who are very sensitive to earthquakes.

Shaking is slightly felt when a person is quiet, but the duration is not long. The shaking is not frequently felt when a person is standing.

II

Weak. Shocks felt by most persons, slight shaking of doors and Japanese sliding doors (shoji).

Hanging objects are seen to move, and slight shaking is felt even when a person is standing, but it is generally not felt when a person is moving. Occasionally a person can be awakened.

III

Rather strong. Slight shaking of houses and buildings, rattling of doors and Japanese sliding doors (shoji). The water surface of a vessel can be seen to ripple.

Felt to be slightly surprising, and sleeping persons wake up, but they do not run outside or feel afraid. Many people outside feel it, but some pedestrians may not.

IV

Strong. Strong shaking of houses and buildings, overturning of unstable objects, and spilling of liquids out of vessel. Felt by walking people outdoors, and many people inside rush outdoors. Considerable swinging of hanging objects such as light bulbs.

Sleeping people jump out of bed, and feel afraid. Electric poles and trees are seen to shake. Some roofing tiles of general houses may slip out of place, but serious damage does not occur yet. Slight dizziness is felt.

V

Very strong. Cracks in the walls, overturning of gravestones, stone lanterns etc., damage to chimneys and stone fences.

It is considerably difficult to remain standing. In houses, slight damage is generally sustained. A soft ground can split or break. Unstable furniture falls over.

VI

Disastrous. Collapse of less than 30% of all houses, landslide, and fissures in the ground. Most people cannot stand.

It is difficult to walk, and one has to crawl to move.

VII

Very disastrous. Collapse of more than 30% of all houses, intense landslide, large fissures in the ground, and faults.