The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1904-04-21

which one layer or strata. or perhaps
a series Of these formations. make up
on some opposing strata. Suddenly
| there is yielding at some point Pres
| to. the strata exerting the greatest
| pressure slips into new position. We
/ have an earthquake The sensation is
usually as though the earth had un-
dulated like the long, sweeping swell
/ of the ocean. The amount OF shock IS
/ in proportion TO the velocity OF the
| earthwave. Sometimes an undulation
| or wave may be very slight. only
| few inches in it's crest, yet so rapidly
| 5oes it move that greater damage is
done than when there is more mark
| ed upheaval which has Travelled more
! slowly The earthquake at Caracas
| was a striking evidence of the former
| The size of the jerk, to speak roughly,
or scientifically the rate of movement
| per second or the acceleration, deter
mines the character of a seismic dis
turbance.
I'm the upper valley of the Hudson
river and in some parts of northern
New England there are probably fault
assures in the earth crust These are
points where a hard, rocky unyielding
series of strata, or layers of matter,
are pressing upon softer, more yielding
material, as sand or rotten rock. Sud-
denly the pressure of the harder mass
es dislodges some of the more yielding
layers; with a snap or jerk the un-
yielding layers slip over the softer
masses or push them out of place.
That is an earthquake. That is what
happened last night. Along the sea-
coast there, is always greater possi-
bility of seismic changes In the
neighborhood of Martha's Vineyard
there are geological faults. Besides,
along the coasts of all the continents
the sections nearer the ocean are push
ing or pressing up the land, and that
is what in the past has formed the
great mountain ranges which are
usually near the coast. The Andes on |
the Pacific coast of South America are
an example The same is true of the |
coast ranges of California, British |
Columbia and Alaska. But it takes |
ages, in which a century is but a brief !
division of an hour, for these changes
to occur I would prefer not to make /
any predictions. Yet 1 may say there |
is but small chance of an immediate |
shock that may be perceptible. If Har- |
ward were equipped with the proper |
instruments, we should probably have /
been able to anticipate this shock.
Please note 1 say only probably
I'm sense most seismic commissions I
may be likened to the rising and falling
of the tide. When the tide is highest,
when wave which rolls highest on the
beach breaks, that is the shock which is
perceptible 1t is probable that there
have been small, unnoticeable tremors
for a time; then inertia and resistance
We're overcome suddenly by the un-
yielding masses Of countless tons of
earth and a new disposition OF the
masses resulted. Now for some time
there may be slight unnoted shivers of
New England's surface as. the heavier,
more powerful masses settle themselves ,
more comfortably in their new posi-
tons. Most emphatically New England
Is but little subject to seismic up
The earth's surface is too we'll | c
settled now to anticipate marked
geological changes. This is shown by
he strata of granite and other rocky
masses and the clayey, cohesive char
tcter of the earthly layers which inter-
vene. There is no section of the crust
If the earth which may not be affected e
~ the shock of a changing in the rel '
tive position of the parts of which it +
8 formed
CRACK CAUSE OF EARTHQUAKE.
Prof Henry Shaler Williams of Yale,
Who was recently elected head of the t
geological department of Cornell Uni .
-ersity, said at New Haven Tuesday .
hat the earthquake felt in New En-
,land Monday, was undoubtedly caused I
~ a slip in a crack of the earth's sur 0
ace. Down deep in the crust, one of p
he two faces of crack moved against o
he other causing the Earring. BY the I
of the two faces, tension I
vas relieved and there is no immediate s
anger of recurrence of the shock. n
'rof. Williams thinks the earthquakeI S
vas probably similar in origin to that T
t Charleston, in 1885, which was the Il
most extensive. of modern times. IT Q
houid say that in extent the one of ;,
tuesday comes next to that in Charles :,
on. The faces which were disturbed !.
nay have been to 10 miles below the :
urface of the earth. Springfield Re- :
ublican.
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