The Opelousas courier. [volume] (Opelousas, La.) 1852-1910, 1886-11-06
Earthquakes.
Scientific American.

What is known and believed about /
earthquakes By geologists was colt
densedl into an hours talk by Professor |
John S. Newberry, in Hamilton Hall, |
Columbia College, at a recent meeting I
Of the New York Academy of Sciences.
An earthquake is neither novel nor
a mysterious occurrence. 1t Is among |
tile most common of terrestrial phe-
nomena. Not an hour, perhaps not a
minute. passes in wliicl, some portions
of the earth arc not vibrating from this
cause An earthquake is movement
caused by the shrinking, from the loss
of heat, of the interior of the earth, and
a falling in of portions of the crust IN
consequence. That the interior OF the
earth is intensely hot is indicated by
wells and mines sunk in all parts of the
world. Heat increases about one de-
gree Fahrenheit for every SO feet below
the earth's surface DR.. Newberry gave
the temperature of different wells in this
country and Europe as demonstrating
this, instancing particularly a well in
Eurepe sunk 1880 feet, at which depth
the thermometer indicated lis degrees,
and another little over mile In
depth, where the temperature was
shown to be l3l degrees. There were
some exceptions to this rule, but the
| abatement that below 1900 feet in Ger.
| tain wells it had been found that the
temperature declined was a fraud. AT
the rate that he had indicated, the heat
/ would be so fervent that all substances
wanld be melted. 1t was believed that
| the earth's crust was thicker than this
would indicate, because the increase of
heat might be slower ut great distance
from the surface Tie heat of the ln-
terror was constantly escaping to the
/ surface Since the outer crust had iost
its heat, it no longer contracted.
Mountain chains resulted from read.
instments of the eafth's surface caused
by earthquakes. The folds and frac-
lures seen in every mountain belt conld
not have taken place without great dis.
turhances, and III every mountain range
are evidences Of many earthquakes In
The highest mountain ranges, like the
Himalayas, the work of elevation is
constantly going on. Displacements
are constantly taking place all over the
world They occur in paroxysms, and
the pressure being relieved, earth
auakes follow AS the population o1
the earth increases, the number OF OBJ
servers increases, aud the loss of life is
eorrespsndingly greater.
In New England, during the last cen
tnry. there have been ii great many
earthquakes In 1927 the country
, about Newburyport wac shaken mp ~
!. the same way that it had been al
Charleston recently, but the damage
VAS small in comparison. Chimney
aud stone walls were thrown down
there were ruptures Of the surface, ane
+, lets of sand were thrown up. In l63'
there was a great revolution in tht
topography OF the country, and a.
shown by Brigham in his work on vol
eanic ernptions in New England from
g 1858 to 1869, there were 23l earth
auakes worth ehronicling during tina
: neriod. besides many smaller ones.
IL has been estimated that the maxi
mum depth of earthquake disturbance
I was 81 miles, aud the minimum =
. miles. The pressure OF subtefraneal
reservoirs OF water are among tii
causes of earthquakes.
I Explosive earthquakes were probabl
], caused by large quantities on Wate
! being brought in contact with molte
lava. and steam had played a large
!, though generally secondary, part
. producing thenl
The theories of Sir William Tlomso
! and others rs to the great thickness
: the earth's crust are now generally cor
J. sidered untenable, aud it was believe
i that it was only about SO miles
depth. It was probable that the VI
E cons zone acted as n buffer between th
, LIQUID interior and The solid crust. III
!. aexlbility Of the crust showed that
. was not of great thickness. The LEI
turer dwplt Rpon the proximate cause
! Of earthquakes, such as atmospher
! pressure, aud said it was not SO absul
8 rs some thought to believe that atm.
J. spheric conditions had something to 9
i with them.
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