Geoscience Reference
In-Depth Information
Table 7.4 Characteristic of the Fujita-Pearson scale (Marshall 2001)
Level
of
scale
Intensity
Wind
speed
(km/h)
Damage
scale
Type of danger
F0
Storm
40 - 72
Light
Some damages to chimneys, bro-
ken tree branches, uprooted trees,
signs torn off the buildings
F1
Moderate
tornado
73
112
Moderate
Lowest wind speed of the early
hurricane. Blows off the roofs,
pools down houses from founda-
tion or turns then over, moves the
cars, can destroy separate or
attached garages
-
F2
Substantial
tornado
113
157
Considerable
High level of danger. Blows off the
roofs, destroys mobile dwellings,
overturns box garages, breaks or
uproots big trees, takes away light-
weight objects
-
F3
Strong
tornado
158
206
Severe
Destroys roofs and walls of sta-
tionary constructions, overturns
trains, uproots the trees
-
F4
Devastating
tornado
207
260
Devastating
Destroys solid buildings, takes
away houses with poor founda-
tions, cars, and large objects
-
F5
Incredible
tornado
261 - 318
Incredible
Throws houses off foundations and
takes them away destroying,
moved cars at distances up to
100 m, breaks trees, heavily dam-
ages steel, concrete-fastened
strictures
F6
Inconceivable
tornado
319 - 379
Maximal
Such winds are improbable. Their
destructions are dif cult to distin-
guish from destructions by torna-
dos of the type F4 and F5. The
emergent vortex exhibit a huge
power over a small territory, it can
take large volumes of water and
transport them at great distances
In most cases, tornado intensity is measured by the Fujita-Pearson scale
(Table 7.4 ) that really re
ects the risk level. It is important to know when and how
the tornado origins. It is known that many tornadoes have their origin as the product
of a tropical hurricane. Therefore, the information about conditions of tropical
hurricane beginning and its tracing are principal stages to predict the tornado origin.
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