Page 3135 - 1970S

While earthquakes most fre–
quent ly occur a long jost li ng pl a te
edges, violent convulsions can and
do occur fa r from the edges.
1n fact , one of the greatest series
of quakes in Uni ted States history
devastated a huge area around New
Madrid. Missouri . in 18 11 and 18 12.
lt was so strong that it reversed the
M ississippi River in sorne places
and creatcd new lakes.
Lucky So Far?
Recent quakes have kill ed tho u–
sa nds a t a time. but for the most
part. they have hit relatively un–
populated land or ocean areas. or in
vi llages with poor building stan–
dards. (Often these villages have
many st ick- frame dwe llings plas–
te red over wit h mud that coll apse in
even a moderate quake .)
Modern construction and heavily
popula ted areas in highly advanced
nations have no t yet been put to a
"great'" qua ke tes t. Yet earthq uake
experts fear hundreds of thousands
could be injured or ki ll ed. beca use
buil din gs. b uild i n g codes, and
human preparations have been
grea tly neglected in many areas.
The earthquake that ripped Nica–
ragua in la te 1972 was a "moderate"
quake (6.3 on Richter sca le), no big–
ger than the early morning Los An–
ge les quake (6.5) of 197 1. Yet ,
downtown Managua resemb led
ground zero a fter a n atom bomb
bl ast. Thousa nds died in Managua
whil e less than 100 died in the Los
Angeles area.
Building construct ion, soi l condi–
tions. and time of day differences
produced a wide d isparity between
these two disasters. Had the LosAn–
geles quake hit during hours o f busy
streets. occupied schools, and facto–
ries. casualties would have been
much highe r.
At the time of the devastating
quake of 1906. San Francisco was
relatively undeveloped compared to
the present ci ty . Today many offi–
cials are a la rmed a t the extensive
housing projects built right on or
along the San And reas Fault tha t
we re not there in 1906.
Earthquake Prediction: Closer
to Reality
In recent yea rs. sc ientis ts have
found that most big earthquakes do
24
not come like a bolt out o f the blue.
Tell-tale seismic evidence wi ll usu–
a lly be present to signalthe impend–
ing tembler.
Many seismologists now theorize
that rocks in the vicinity of the fu–
ture earthq uake break apart slightly
und e r increas ing p ressure. As a re–
su lt. the speed o f sound waves pass–
ing through the e frac tu ring rocks
slows down sli ghtly as the rocks be–
come filled wi th greater amounts of
a ir. Ma ny of th ese scientists feel that
as water fills the minute cracks, a
return to norma l sound-wave mea–
surement occu rs. In severa! cases.
this " no rmal izing" has been th e tip–
off that a quake is a bout to str ike.
Changes in tiltmete rs, creepmeters,
electrical conductivity, and magne–
tism in the ea rth a lso may be addi–
tiona l tip-offs.
Already, as a result of using de–
tectable changes in the ea rth , sev–
e ra! ea rthquakes a round th e world
have been predicted accurate ly as to
place. a pproximate time. and mag–
nitude. (However, it is not known
how many other p redictions have
failed .)
The mos t s ta rtling s uccess in
ea rthqu ake prediction occu rred in
the Ma nch uri an provi nce of Lia–
on ing in China in late 1974 and
ea rly 1975. As a result of numerous
ins trument-recorded premonitory
signs (as we ll as signs from alarmed
an ima ls: ca ttle behaving fitfully,
frogs jumping through holes in ice
on frozen ponds. ra ts su rgi ng from
the ir dens) vill ages in severa! Chi–
nese cities we re evacuated severa!
days before a devastating 7.3 quake
tore the area. The town of Haicheng
was leveled. Beca use of the advance
o rde rly evacuation. casualties we re
large ly among those who refused to
heed the wa rning.
Late las t year, Dr. James Whit–
comb of Cal~ec h' s Seismology
School s uccess fu ll y predicted a
moderate quake east of Riverside,
Ca lifornia. He pred ic ts another for
Southern Ca li forn ia in th e 5.5 to 6.5
magnitude range by May ncxt yea r.
However, some public officia ls
point out ea rthquake predictions
could be a curse as well as a bless–
ing. "A prediction i tself could in
sorn e ways be worse than a n act ua l
earthquake," says Dr. Vincent E.
McKelvey, director ofthe U.S. Geo-
logical Survey. "Visions of sta lled
eco nomic grow th . thousa nds of
autos streaming over bridges in a
mass evacua tion are frig htening in–
decd. Many would rather take their
chances wit h no warning."
St ill. most se ismo logists feel they
have a moral obligation not to keep
scc rets and to a t leas t give a warning
to responsib le gove rnment and pub–
lí e agencies.
What Can Be Done?
Th e ene rgy released in a major
ea rt hq uake could act ually be more
th an severa ! hydrogen bombs. It
would seem that governmen ts that
sca rcely flick an eyebrow lo spend
addit iona l millions or billions of
do ll a rs on milita ry defense should
expand their (so fa r usually meager)
budgets for ea rthquake research
and p rediction.
Nex t, it is vital to upgrad e build–
ing codes and improve their en–
fo rcement. Dr. C ha rl es Richter, the
famous seismologist who developed
th e sca le bearing his name. says.
"Ninety percent of the loss of life
[from earthquakes] resu lts from the
co llapse of structures that a ny engi–
neer could have established as un–
sound." T hese deaths and half of
the property losses a re unnecessary
and preventable, according to Rich–
te r.
Well- built. mode rn. steel-framed
skyscrapers are. in most cases, safer
from complete collapse than lower.
multi-story buildings built before
ea rt hq uake codes were enforced.
Yet equally as important as good
earthqua ke structural engineering
a re the surface conditions upon
wh ich a building re t .
An area underlai n by unstable
ground (sand , clay, volcanic rubble,
or o ther unconstituted materials) is
likely to experience much more
damage than an a rea equally dis–
tan t or even nearer the earthquake
epi center but underlain by fi rm
ground such as granite.
Apart from th ese considerations,
the most the average ind ividual can
do is prepare himse lf o r herself to
act as calmly and sensibly as they
ca n before, during. and after an
ea nhquake.
The fo llowing page contains some
soÍ.md advice from earthquake and
sa fety experts. o
The PLAIN TRUTH September 1976