The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1886-09-10
EARTHQUAKES.
Their Origin and Lines of Occurrence-Scien-
tific Suggestions.

Their Origin and Lines of Occurrence-Scien-
tific Suggestions.
Prof. Richard Owen, in Evansville Journal.
The recent destructive earthquake has aroused
public attention to seismic phenomena, includ-
ing the laws governing the transmission and dis
tributon of the interior disturbing force which
sometimes finds vent for its tension by volcanic
outbursts, at other times shakes the earth with
tremors, or under less resistance breaks entirely
through the crust, occasionally with most dis
astrous consequences.
Having, for good many years, made this sub.
iect my special study, and read or sent to be
read at meetings of the A. A. A. S. suggestions
relative to the laws governing these movements,
perhaps popular statement of some of the lead
ing generalizations and their applications to
everyone of the places recently disturbed in the
old W orld and on our own continent, may be &C,
ceptable as being suggestive
In order to make the application of suppose
laws to facts more ineligible it may be we'll to
offer few preliminary remarks. Over twenty
years since l showed that eastern continental
trends ran from the Arctic 10 the Antarctic cir
Gle. forming angles of 23!o wiz: n. 23ao e. with
neridians while their mates interesting them at
the equator, and running N. 1910 w. often define
w. coasts.
Later | showed that these great circles were
equldlstant, namely, beginning at the coast of
Asia and running through the Straits of Macas-
sar we have great circle, which we may call
"a" and 72o Tor 360o:-5) west of the straits we
find the great circle which defines the east coast
of Africa OBJ; 72o further west "C defines the
coast of South America, and still 72o west cd"
runs along between our Atlantic coast and the
Appalachian range The last of the great cir
cles ("E"l marks where the archipelago Of the
Paclhc presents the mountain peaks of sunken
continent, Oceanica. Such was the conclusion
of Darwin, after close investigation. The west
running hester to the above great circles called
A, B, G, D, E. The former can be readily
traced on any good globe, by elevating the north
bringing these coast lines SUCCESSFULLY TO the
horizon. By depressing the north pole 23Io,
and revolving as before, A, B, G, d and + can
be readily traced along the wooden horizon
Many scientists assign as one cause of earth
quakes the shrinkage of the crust, sinking in of
rocks and consequent disturbances of the ten
sion, and perhaps of the molten materials These
phenomena would be most apt to occur along
the weakest portion of the crust, which is gerer-
ally considered to be along these continental
lines that naturally are weakened by the rise of
land on one side and the oceanic depression on
the other. 1t seems reasonable. then, to expect,
that which We actually find, that volcanic out
bursts and earthquake disturbances should occur
along these weakened great circles, and often be
propagated along the mountain strike parallel
to the COAST rather than across a variety of
heterogeneous rocks, soils, ETC. Another gener-
aiization OF la seems to be that earthquakes are
apt to occur on great circles between one vol
canic region and another. Let US apply this law
to some of our great circles. In tracing the great
circle "a, it may be noticed that 1t marke and
connects the numerous volcanoes Of Kamtchat