Evening star., 1935-05-19
EARTHQUAKE PREDICTION
DEVELOPING AS SCIENCE
Citizens Throughout U. S. Are Asked
to Cooperate by Reporting on
Earth Movements.

The Atlantic region, within so miles
Of the coast, about one cent.
The Great Lakes and Mississippi re-
gion, below Missouri confluence and
within 10 miles of bottom lands, about
two cents. f
The Great Lakes and Mississippi
region, remainder, about one cent.
The Great Plains and Midcontinent
region, about one cent. 80
The Rocky Mountain-Wasatch re-
gion. about three cents.
Washington and oregon, within 100
miles of the coast about six cents.
Washington and Oregon, rest Of re-
gion, about cents.
California Mountains, east Of the
great central valley, about seven cents.
California. within the great central
valley, about five cents.
California, within so to go miles
from the coast and including the I'M
perial Valley, about 10 cents.
It was estimated by the head Of one
insurance company that the mere
business overhead" of writing an
earthquake insurance policy, even for
California, would cost his company
more than the average quake hazard.
In the light of this evidence you
ought to be able to go ahead and enjoy
your earthquake and report what
happens in your vicinity so that the
geologists and seismologists will be
helped in tracing fault lines.
Though the tremor may be very
slight, the mere fact that it was felt
may be of Importance, even without
IaA- HrN
vicinity and your report may help
scientists to work out important data.
A simple postal card to your nearest
postmaster will be sufficient; he al
ready has instructions what to do.
Earthquake prediction, of course, Is
not the most important objective of
this new intensive study of the earth's
crust; its importance lies in the fact
that it will solve vital missing links in
fields of practical engineering.
If you desire-rememberi that
human beings cannot feel the vast
majority of earthquakes at all-you
may observe some of our natural living
seismographs, perhaps in your own
back yard. Sometimes days before
a perceptible quake, when the earth is
swarming above ground because their
earthly shelters are being slowly COM
pressed. Squirrels and rodents may
be driven out of the earth, and they
often migrate in considerable numbers.
Chickens and other roosting fowl are
always restless during night of earth
movements.
DR.. Ray Lyman Wilbur, president
of Stanford University, says that
there have been recorded on the seis-
mographs there more than 200 shocks
in a year, of which not more than
one or two could be felt by "the man
on the street"
Quake Predicted Accurately.
Bailey Willis, professor emeritus Of
geology at Stanford, few years ago
achieved the most remarkable feat Of
earthquake prediction yet known. In
1928 he made this statement:
"I regard it as probable that in
Southern California there will be
severe shock which is more likely to
come in three years than in 10, and
more likely to come in five years than
in three"
Five years exactly elapsed to the
time of the Long Beach quake in
March, 1888. Prof. Willis made his
prediction on the basis of strains he
had observed in various fault-lines;
that is one phase of earthquake pre-
diction.
Bringing into a single prediction
system the strain observation method,
the tendency of strains to be relieved
along the big adjacent blocks, the cycli-
cal effects Of sunSpot pressure, the tidal
effects created by the moon and an
orderly mass of readings from delicate
instruments properly located, seismol-
ogists hope to give us fairly good pre-
dictions-and leave 1t to future in
vention and discovery to refine the
whole process.
Seismological stations equipped
with notwithstanding inStru-
ments are rapidly multiplying in the
United States. There now are so
such stations in the country, while
Government bureaus and the Car
negie Institution have a number Of
portable instruments ready to rush
from strategic points to cover" emer-
gency situations involving opportuni-
ties to obtain information.
Such an emergency situation re-
Gently occurred in Southern Cali
fornia, when mysterious destructive
fair-weather tides began arriving on
narrow strip of beach front. On
islands off the coast and at points
along the mainland portable instru-
mentS were placed in an attempt to
discover what submarine catastrophe
might have caused the great tides.
There is great co-tidal effect be-
tween New Zealand and Southern
California; along narrow strip Of
sea the water tilts back and forth as
though it were in a bowl that was
being lifted at one end and lowered
rhythmically. The rhythm was sud-
denly stepped up, with great destruc-
ton of beach property in both New
Zealand and California.
Tides Attributed to Storm.
No readings of distant Pacific
earth-crust movements could be OBJ
tanned, and oceanographers finally
ascribed the tides to a storm perhaps
midway between New Zealand and
California, of regular steamship
lanes.
If submarine earthquakes could be
proved to be the cause of the great
acceleration in the big co-tidal system,
then permanent stationing of instru-
ments at appropriate points might in
some instances result in detection Of
earth. movements as they occur, with
prediction several days in advance Of
the arrival of destructive tides
In California every opportunity Is
graSped to study vibrations in the
earth. Scientists want information
on everything from characteristic
shocks which will enable structural
engineers to build better buildings, to
data on the composition of the deeper
parts of the earth'S crust and even Of
the earth's core. The latter data are
particularly sought when the seismol-
ogists study quakes occurring far
enough around the world for the
waves from them to have to proceed
through part Of the planets core.