Geoscience Reference
In-Depth Information
Table 5.3
Modified Mercalli and Richter Scales
Magnitude
Scale
Modified Mercalli Scale
I
Detected only by sensitive instruments
1.5
Felt by few persons at rest, especially on
upper floors; delicately suspended objects
may swing
II
2
Felt noticeably indoors, but not always rec-
ognized as earthquake; standing autos rock
slightly, vibrations like passing truck
2.5
III
3
Felt indoors by many, outdoors by few, at
night some awaken; dishes, windows, doors
disturbed; standing autos rock noticeably
IV
3.5
Felt by most people; some breakage of
dishes, windows, and plaster; disturbance
of tall objects
V
4
Felt by all, many frightened and run out-
doors; falling plaster and chimneys, damage
small
VI
4.5
Everybody runs outdoors; damage to build-
ings varies depending on quality of construc-
tion; noticed by drivers of autos
5
VII
5.5
Panel walls thrown out of frames; walls,
monuments, chimneys fall; sand and mud
ejected; drivers of autos disturbed
VIII
6
Buildings shifted off foundations, cracked,
thrown out of plumb; ground cracked; under-
ground pipes broken
IX
6.5
Most masonry and frame structures de-
stroyed; ground cracked, rails bent, land-
slides
X
7
Few structures remain standing; bridges
destroyed, fissures in ground, pipes broken,
landslides, rails bent
7.5
XI
8
Damage total; waves seen on ground sur-
face, lines of sight and level distorted, ob-
jects thrown up into air
XII
Source: Modified from Steeples, D.W., Earthquakes: Kansas Geological Survey
pamphlet, 1978.
 
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