Evening star., 1923-10-01

continues to live where these great
movements are in progress.
Scientists have known since 1906,
when the great San Francisco earth
quake occurred, that at least part
Of the California coast ranges was
marching northward, DR.. Willis said,
but 1t took the Chilean earthquake
of November, 10. 1922, to show them
that the Andes were just as slowly
but steadily shifting eastward over
what is now the Argentine Republic
The movement in each case is away
from the ocean, and the eastern part
OF Japan is probably moving west
ward.
Elastic Rebound Theory.
Referring to the causes OF earth
quakes, DR.. Willis said that his five
months field work in the Chilean area
had confirmed the theory of elastic
rebound as a. prime condition of
earthquake vibrations. In explana-
ton he said there is a mass of rock
there. whicS may be considered TO be
1000 miles long, 600 miles wide and
100 miles thick. This pile is being
pushed eastward by the changes in
side the earth. 1t moves just so far.
the pressure becomes too intense and
the whole mass snaps or jumps back
some distance. The result is an
earthquake.
The same kind of change. he as
serted. is pushing the Andes noun
tains over Argentina. How fast they
are moving science has not yet learn
ed. but that they are moving has
been proved beyond a doubt. In the
Chilean earthquake sector. he said,
there is a nearly nat horizontal fault,
which originates under the Pacific
deep and reaches up into the Andes
mountains. 10000 feet above sea level.
Vast Area Affected.
While the Japanese earthquake was
much more severe, DR.. Willis con-
tinued. it was not nearly so extensive
as that in Chile in 1922. The former
covered an area of only approximately
10000 square miles. while the Chilean
quake shook 100000 square miles, or
100000 cubic miles if it were only
ten miles deep.
II have said" the noted geologist
remarked, that I was sent to South
but they let a venomous little one get
away while I was absent"
There Is no doubt, DIR. Willis stated,
that both quakes were caused by the
same conditions. but each originated
in widely separated and distinct GEN.
ters
Points Out Differences.
Describing the difference between
the California fault and the Chilean
fault, DR.. Willis pointed out that the
former is vertical while the latter is
horizontal. In the case of the CAL
ifornia. he said that science can even
estimate roughly the rate at which
the western section of California is
moving, since measurements made by
the coast and geodetic survey DEM
onstrated changes of position OF their
station.
Repeated observations have shown,
he continued, that the stations es-
tablished by that survey have moved
three feet or more in a period OF ten
or fifteen years. Upon the occurrence
of an earthquake. however, the sta
tions sprang back part way into their
original positions, proving again the
theory of elastic rebound as d prime
condition of seismic vibrations. The
theory works upon the same principle
as that Of a steel spring being slowly
pulled aside until ii snaps back.
Records Twenty-FoOt jump.
Science has confirmed that the hori-
zontaI jump of the mass IN CaHtoT.
mia during the earthquake OF 1905
was twenty feet. DR.. Willis added
that there is every ,s reason 70 o. oeissTs Hasrs
since the displacements began the
mountain ranges of California have
slipped many miles past each otheT.
The Andes. he said. may be spread
ing over Argentina at the, rate or
meter a century-perhaps two or
three meters. >.
DIR. Willis said the. cause of these
vast geological changes is 20 oe
found inside of the earth. Molecular
forces. are brought into action my ey
heat and pressure. causing rocks
under q great deep like that Off the
coast Of Chile or Japan to expand
horizontally while they shorten YER
tically That force then may be de-
veIoped into a mass 1000 miles long,
600 miles wide and 100 miles deep
and would be sufficient to cause the
movements observed. -
part OF DR.. Willis mission to Chile
was to study the condition, of houses
in the earthquake area and endeaVor
to develop q structure that would be
uualseproof. He believes that prob
lem has been solved. One of the first
stems, he said. is to discard nails in
a country subject to earthquakes and
substitute wooden pegs and fence
wire. the latter to tie stimbers to-
gether.