The semi-weekly messenger. [volume] (Wilmington, N.C.) 1897-1908, 1906-09-11
CAUSE OF
ineory Of n Noted Scientist a. 70 the
Recent Seismic Disturbances

49, bas'S were no II
number, n al about 6:5s a. n. on
Aug Il, and the other at about 9 "a
q N This interval Of three hours be-
tween the two asst shocks Is very suE-
eesuVe IL movements which have run
round the world. OF course In Val
a" -se;* AMI the ne!ghoorhoot
probably many thousands OF small
shocks will occur before the dis,-icr
settles down 10 its normal state.
These earthquakes are probably due
10 the faulting or breaking Il strata.
WHICH are being buckled upward in the
process Of mountain formation The
Ande rise I . 4 height ~ l2.0+0 feat
while Immediately in front Of them i
ocean 1850 feet in depth. These
deeps run along the western shore OF
South America and from an oceanic
trough. From the bottom Of this
u 10 he summit OF the mountain
the slope Is about one in twenty. and
IN all parts of the world where We ind
steep slopes OF this character having a
length. let us say, Of two geographical
degrees, or l20 miles, We find that We
are IN a district Of instability and are
fracturing frequently takes place.
geographically speaking, these steep
slopes are of recent production and We
hnd many evidences along the coast
line where they occur Of recent elcva-
ton or depression genera. ~ tie form r
Indicating that the ground IS still being
buckIed. Accompanying this process
sudden Weddings from time 10 time take
place and are announced 10 the world
as large earthquakes.
What causes these ven is
more or less a matter of CONJECTURE.
1t may be due 10 the contraction Of the
nucleus of our world through loss OF
heat, leaving behind it a crust which is
not strong enough to support itself,
and therefore. as it falls inward 1t Is
bent and broken. That is an operation
dependent upon internal change with
in u earth resulting from loss Of
world heat. An operation which also
might effect earthquake frequency may
be traced backward 10 sun heat. From
sun heat we get evaporation of m0is-
ure to form our clouds, which are pre-
clpltated as rain, forming rivulets and
rivers. These are continually taking
iAS1ANl AaIS IIclI liz - IIltS vi al r.
nents, or, in other words, removing
loads, in the form Of sediments, which
are carried down to be deposited event
uaIy on the sea bottom.
If W can imagine the crust of our
world to be supported by fOtation the
general result is a sinking where the
materials are accumulated, whereas
the other part from which the mater
1n1c how I1n~ Wv +z~l~ - r;-D A.
an accompaniment of such movement
it is easy to imagine that sudden yield
ing should take place.
Many of the earthquakes on the
South American coast lave been of
~sub-Oceanic origin, but on this Occas-
ion, inasmuch as we have not heard
of sub-Oceanic cable Interruptions or
Of large sea waves, it seems likely
that the OPTICAL area is to be found
on the land. and no doubt it will be
traced to the faults running a cOnsid-
cradle distance southwark or north
ward from Valparaiso. For more than
10 years this part of the world has
been %singularly free from very large
earthquakes. A very large one occur
red on May 9, in 1877. 1t was accom-
panied by large sea waves, which trav-
ened over the whole of the Pacific
ocean. They reached Japan, distant
about 5000 miles, in "a hours, and on
their arrival at that country they were
six or seven feet in height and each
of them 100 miles in length. When
earthquakes of this sort occur, which
shake the whole of our globe and dis
turb so vast an enpanSe of ocean, we
may naturally speculate as to the mass
of the material which was suddenly
moved to produce those astonishing re-
suits. If we drop a stone about OF
inch in diameter i'll a pond it will SEND
waves some 20 or 80 feet. To produce
such oceanic waves as we have des-
cribed, if We can trust the rule OF three
the displacement in the Pacific NIGH
have been made by something equiVa-
lent to a stone several hundreds Of
miles in diameter.
From measurements now being made
in the devasted area of California I
would seem that movements OF SOM
six feet or seven feet have taken plac"
along lines approaching 800 miles in
length. The breadth Of the area OF
about so, 900 square miles mas oe'n
shattered. There are many reasons
W0Icn NOlIu ICdu 10 W tHl%~t -"
these faults may extend through what
is called the crust Of the world, or to
a depth. let US say. of 80 miles. The
inference from this is that nearly >
600. OOO cubic miles Of rock nave been
suddenly shifted. Such estimates may
be run up TO To- 900, 900 cubic miles. 1t
is the impact OF enormous masses IKE
these which gave rise TO 1.-THE lnitia!
imnulsa which set the whole of our
world in a state Of vibration.
similar character occurred IN 1917,
similar characters occurred in 1865,
sending lis sea waves across the Pacin1
TO alarm the inhabitants Of Japan, "ho
in, many cases removed their nous
hold goods 10 high places for the sake
If security. The more classical earth
ouakes occurred in 1885 and 1891 Tn@
first was felt for a distance Of neaTl:
l o miles along the Chilean coast II
was accompanied by elevations Rocks