News and citizen. [volume] (Morrisville, Vt. ;) 1881-current, 1886-10-07
Earthquakes and Tidal Waves
PROFESSOR ABBE DISCUSSES TIL { RECENT
DISTURBANCES AND PREDICTS A Long
REST,

Professor Cleveland Able, of Wash
ington, made a very extensive study of
earthquakes and the theories regarding
them. His views are outlined as follows
Professor Able considers the Charles
/ ton earthquakes to belong to the same
/ category as that which was SO violent
/ at Long Branch on August 10, 1884, and
which was felt from Maine to Virginia
4 and westward to Ohio. About one hun
dred and fifty such earthquakes occurred
between 1872 and 1882, and were stud
led in the article by Professor Able
i published in the Herald on August II,
! 1884. In this article Professor Able
concludes that these shocks originated
above the Archaiean strata and in the
! lower portion of the sedimentary depos-
( its-namely, from one to five miles be-
/ low the earth's surface. He holds that
! there is no reason to believe in hot
! fluid interior, but that probably the
/ rocks beneath this portion of the sur
| face of the globe are in condition of
/ considerable constraint due to several
causes-namely, first, the weight of SUI
I perincumbent masses; second, the con-
! traction due to slow cooling Or the ex-
{
! cal changes are still going on third, the
strain due to bending; and fourth, the
! strain due to the slow process of crys
/ Utilization, such as occurs in the forma-
/ tion of bikes CT masses of granite, mar
| BILE, &c Under these accumulated
! strains the rocky strata are perpetually
cracking, sliding on each other, resting
and again giving way. Every fault"
met with in mine or quarry means a
slight earthquake.
If it were not for the myriads of little
quakes we should have to do only with
greater earthquakes, which would in
fact be of the nature of terrible
paroxysms. When a'severe earthquake
happens it is usually proceeded and fol-
lowed by numerous slighter quakes, in
dicating that the strata are gradually
being relieved of their strained condi-
ton, but that the main relief is found
in the MAN shock.
The distribution of the one hundred
and fifty Appalachian earthquakes
shows that numerically they are least
frequent from May to September, but
that these are precisely the months
when the severer earthquakes are likely
to occur; and, again, that a period of
few earthquakes is especially likely to
be followed by one or two severe ones
that become stronger the longer the
period of dearth has existed.
Charleston lies precisely in the region
where the earthquakes have been least
frequent for the last fifteen years. Ac-
cording to the study made of the num-
Der of earthquakes already mentioned,
the whole country is now entitled to a
period of rest at least as long as those
between the earthquakes of Boston, in
1855; of New Madrid. in 1911, and the
present one of 18S6-namely, from fifty
eight to seventy five years.
With regard to earthquake tidal
waves, there was from the beginning no
occasion for fear in the present instance.
The waves in 1855 in Europe and Amer
lea, that of India, in 1919; that of st.
Martins, November 10, 1855; that of
Callao, 1886; Africa, August, 1868, and
Conception, February, 1885; that of
Japan, December %, 1854, and that of
Krakatra, July, 1888, all illustrate the
general principle that ocean waves at
tend only such earthquakes as originate
under the ocean or on the immediate
coast The ocean water must receive
a nearly vertical shock In order to start
the wave. Shocks that originate under
the continent some distance from the
ocean strike the latter with nearly
horizontal movement; so far as our rec
Ords show these appear never to pro-
duce severe earthquake ocean waves, at
least not in the neighborhood of their
origin. If any such wave attended the
Charleston earthquake it would be felt
in the Bermudas and Europe rather than
on our coast.