The Plymouth tribune. (Plymouth, Ind.) 1901-1911, 1905-07-27
ORIGIN OF EARTHQUAKES.
FRESH LIGHT ON OBSCURE AND
MYSTERIOUS SUBJECT.

The Scientific Study of Seismatic
Disturbances is a Development of
Single OBSERVATION-DISCLOSURES
Now Being Made All Over the
World.
Details are too meagre to enable
us to Judge of the full extent of the
calamity which has befailen Cash
mere and the Punjab, but, If the re-
ports from Dharmsaia are correct, the
present earthquake is one OF the most
serious in recent years, possibly ex-
ceeding in the aggregate OF its cas-
ualties the disturbances in the Riviera
in 1887, the Ischia earthquake of 1883
and the disastrous visitation at Ma
Mia in 1880, while it may equal the
more recent earthquake in Japan In
1891, when nearly 1900 persisted; in
Bengal and Assam in 1897, when the
deaths numbered 5000, and in Rus
sian Turkestan in 1902, when upward
of 1900 were killed.
These great disasters, appalling
though they were, fade into compare
tive insignificance when contrasted
with earlier earthquakes of which
more or less accurate records have
been preserved. To go no further
back in history than the close of the
seventeenth century, the earthquakes
in Sicily, which in 1893 killed 100000
of the inhabitants, may be recalled;
and the century which followed was
full of like horrors. Nearly 100000
persisted at Jeddo, Japan, in 1903;
$4,000 in Pekin, in 1881; 10000 in
Cairo, in 1854; $4,000 in Guatemala,
in 1773; nearly 10000 in two Peru.
Wan earthquakes; and, of course, the
great Lisbon disaster of 1775, when
from $4,000 to $4,000 persisted in a
few minutes, will not be forgotten.
In the nineteenth century, in addi-
ton to those TO which allusion has
already been made, the record must
include the destruction of Aleppo.
with $4,000 of its people, in 1922, and
the various South American and West
Indian visitations, which cost many
thousands of lives.
In the nature of things minute rec
ords of great earthquakes have been
preserved from remote periods, but
the scientific study of the subject is
a development almost of single gen.
Grafton. Until instrumental methods
of measuring the force, motion ant
direction of the earth vibrations were
perfected, the actual scientific work
which was done was little more than
descriptive. At present, observations
all over the world are being systema-
tized and co-ordinated, and while
modern seismology has much to do
and many problems to solve, it has
cleared away many misapprehensions
and given the world a clearer notion
of the causes which produce these
great disasters.
The delicate observing instruments
show that, instead of being occasional
phenomena, earthquakes are going on
pretty much all the time; it is only
when the displacements are violent
and the motion communicated to the
earth's crust extremely rapid that
they become at all dangerous.
There are various originating
causes; volcanic action is one, but
those resulting from dislocations OF
the earth's strata-due to inequalities
of stress, the result of the shifting OF
loads by the denudation on land and
sedimentation at sea-have been by
far the most numerous and most i'm
pressive. While volcanic eruptions
have undoubtedly caused earthquakes.
the greater number can be traced to
no such origin, the areas of instabil-
ity in the earth's crust, and therefore
of earthquake frequency, being those
which present the greatest differences
of topographic relief, not the great
est number of volcanoes.
Sometimes these dislocations OF
slips occur on the surface, sometimes
far below, and the location and mag
nitude of the disturbance are measur-
ed by the direction, force and rapidity
Of the vibrations in the earth. 1t is
only necessary to note that most OF
the great earthquakes which have
shaken Japan had their centers not
on the land, where there are many
volcanoes, but on the great slope of
the sea bottom which leads down to
the Tuscarora Deep, to indicate the
reasons for the theory which asso-
ciates these phenomena with purely
geologic forces.
If earthquakes are no more than
elastic wave motions in the solid
crust of the earth, seismologists are
right to concentrate their efforts upon
the investigation and measurement of
those motions. They have already
achieved marvellous results in tracing
to their sources the vibrations which
the seismographs reveal AID record,
and they will doubtless throw fresh
light upon a subject which has long
been mysterious and obscure
Philadelphia Ledger.