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nation's political and economic
affairs.
One major area of concern
among seismologists involves the
stresses developing in the North
American continent.
" New" Earthquake Count r y
Many citizens across the United
States and Canada are unaware of
the earthquake stresses brewing
scale) focused around the New
Madrid, Missouri, area.
So powerful were these quakes
that they destroyed great forests,
upheaved and tore apart major land
areas and changed the course of the
mighty Mississippi river. "The
whole land was moved and waved
like waves of the sea," wrote one
eyewitness.
Few lives were lost in these
Earthquake preparedness reaches a high level in Tokyo, Japan.
Above, schoolchildren study activities they may need to do during a quake.
under their feet. While earthquake
activity is most common near the
Pacific and continental plate edges
in the Far West and in western
Canada, there are also powerful
midcontinent (midplate) stresses
building up. Major population cen–
ters in the East and parts of the
Midwest are vulnerable.
U.S. government scientists estí–
mate that 70 million of the nation's
citizens live in areas of moderate to
major earthquake risk. At least 39
states have suffered sorne earth–
quake damage in this century.
Midwest Time Bombs
How many are aware that the most
powerful series of earthquakes
since the founding of the United
States did not occur in Western
states? The series occurred in the
Midwest in the years 1811-12.
Three great quakes (estimated to
be 8.6, 8.4, 8.7 on the Richter
24
quakes because only a few thousand
then popu1ated the area. But what
was wilderness in 1811 has become
the populous industr ial heartland of
America. Twenty miÜion persons
now live in the area of greatest dan–
ger, and a great concentration of
business and commerce flows
through this region.
St. Louis University seismologist
Otto Nuttli warns there again is a
haunting geologic jack-in-the-box
coi led deep in the mjdriff of Amer–
ica, waiting to pop. He warns it
may not pop for more than 100
years or it could go off tomorrow.
No one knows for sure because not
enough is known about the geologic
structure and fault history of the
area.
The New Madrid Fault Zone
runs through southern ll linois,
southeast Missouri and northeast
Arkansas. Sorne scientists believe
southwest Kentucky, western Ten-
nessee and northern M ississippi
may be involved.
Earthquake stress energy has
been building up for more than 170
years like a wound-up stressed
spring. A repetition now of a great
earthquake, Mr. N u ttli says,
"would cause a disaster whose mag–
nit ude would only be eclipsed by an
all-out nuclear war."
" l n the Middle West, " says
M r. N uttli , "you see your relatives
move to California and you say,
'Watch ou t for the earthquake.'
Midwesterners don't realize they're
standing on one."
T he basement rocks under the
state of O hio Iie between two major
rift zones. "The only people that
really know about the pending dan–
ger are the scientists," said author
Ron Redfern in an interview. Mr.
Redfern's graphically and pictorial–
ly illustrated book
The Making o¡.
a Continent
outlines the geologic
features of each section of the
North American continent and the
massive forces that created them
over time.
What makes a great earthquake
in the Midwest so dangerous for
American security is that a big
quake would almost certainly rup–
ture the major oil and gas pipelines,
railroads and highways linking the
nation.
Many soils in the Midwest earth–
quake zone are particularly vulner–
able to a shaking by a great earth–
quake. The unconsolidated sedi–
ments of the Mississippi valley are
very susceptib le to earthquake
damage- the earth under strong
earthquake vibrations will actually
liquefy under high water content or
high water levels.
Despite general knowledge of
earthquake danger in this region by
officials and citizens, surveys have
found little concern for building
earthquake-resistant structures.
Politically and economically, the
earthquake danger is an unpopular
subject.
East Coast Quake Zone
In J anuary 1982 many East Coast
residents of the United States were
su rpr ised when a moderately severe
ear thquake (5 .9 on the Richter
scale) struck the New England
states. They shouldn't have been.
Earthquakes are recorded common-
The PLAIN TRUTH