Not felt except by a very few under especially favorable conditions
PEAK GROUND ACCELERATION
Less than 0.0005 g
(g = 9.81 m/s²)
USGS Intensity II
PERCEIVED SHAKING
WEAK
COMMENTS
Felt only by a few people at rest, especially on upper floors of buildings
PEAK GROUND ACCELERATION
0.003 g
(g = 9.81 m/s²)
USGS Intensity III
PERCEIVED SHAKING
WEAK
COMMENTS
Felt quite noticeably by people indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated
PEAK GROUND ACCELERATION
0.003 g
(g = 9.81 m/s²)
USGS Intensity IV
PERCEIVED SHAKING
LIGHT
COMMENTS
Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably
PEAK GROUND ACCELERATION
0.028 g
(g = 9.81 m/s²)
USGS Intensity V
PERCEIVED SHAKING
MODERATE
COMMENTS
Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop
PEAK GROUND ACCELERATION
0.062 g
(g = 9.81 m/s²)
USGS Intensity VI
PERCEIVED SHAKING
STRONG
COMMENTS
Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight
PEAK GROUND ACCELERATION
0.12 g
(g = 9.81 m/s²)
USGS Intensity VII
PERCEIVED SHAKING
VERY STRONG
COMMENTS
Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken
PEAK GROUND ACCELERATION
0.22 g
(g = 9.81 m/s²)
USGS Intensity VIII
PERCEIVED SHAKING
SEVERE
COMMENTS
Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned
PEAK GROUND ACCELERATION
0.40 g
(g = 9.81 m/s²)
USGS Intensity IX
PERCEIVED SHAKING
VIOLENT
COMMENTS
Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations
PEAK GROUND ACCELERATION
0.75 g
(g = 9.81 m/s²)
USGS Intensity X
PERCEIVED SHAKING
EXTREME
COMMENTS
Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent