The Monitor. [volume] (Woodstown, N.J.) 1884-1892, 1889-08-30

Submarine Valleys Along the California
Coast-"ShalIow Water" Six Thousand
Feet in Depth--A Horn shaped Plateau
That Serves rs IA Connecting Link
The popularity of the Pacific ocean Is
that it can be divided into two distinct
parts, the dividing line being the merid-
ian of 80 degs. west The eastern half,
that which laves our shores, is remark
able for the absence Of islands and the
uniform nature of its depth, for, with the
exception of the narrow strip of shallow
water surrounding the Aleutian Islands,
and running along the American coast,
the sounding line shows an average depth
of from 1900 to 5000 fathons, undiversi-
fed by any remarkable elevations or de-
pressions The only noteworthy eXcep-
ton to this great and equal depth ia a
great submarine plateau, which extends
out from the Patagonian coast, and which
rises to between 1900 and 900 fathems
from the surface This plateau is horn
shaped, and is evidently n connecting
link between the South American con-
tinent and the Australian archipelago
PARTIALLY ENCLOSED SEAS.
The western half of the Pacific ocean
is a complete contrast to the eastern.
Archipelagos and scattered islands are
exceedingly numerous, and the depth OF
the ocean is uniform, shadows occurring
scattered over it at irregular intervals
Along the Asiatic coast and between the
island groups there are a number of par
tally inclosed seas, and these are sepa-
rated from the great ocean by submarine
plateaus CT sufficient extent and height
to warrant the supposition that mod
crate upileayal would extend the Asiatic
continent as far south as Australia,
transforming the seas into inland salt
lakes. Considerations of the peculiar
animal and vegetable life Of New Zea-
land and Australia lend probability to
the speculation that these islands were
Joined to the main continent of Asia at
some remote period, and it is even posi-
BILE to trace the submerged coast line of
the great continent which then existed.
The same upheaval acting upon the pla-
teau extending out from the Patagoniar
shore would almost make the Pacific
land locked ocean, the entrance to it be-
ing between the point of the new land
stretching out to 121 degs. east latitude
and another headland formed by what is
now Ducie Island, lying in the same lat
itude, but about 10 degs. further north.
As has been said, there runs along the
American shore narrow strip of shall
low water, but the term shallow is only
to be taken in its comparative sense. 1t
is from so to 200 miles wide, the depth
running from nothing to 1 200 fathoms.
Outside this again is another strip of not
quite so uniform Il width, wherein the
depth reached 1900 fathoms, quite deep
enough to drown tall man. Tie uni
form character of the seas depth is
quite marked along the Californian
shore, but even here there are ups and
downs, shadows and depths. The coast
line has strip of water as its imnedi-
ate border, in which the depth keeps at
about twelve fathoms along a ledge or
plateau for few miles out, and then
drops sheer down for 500, coo and 1000
fathoms. This shore ledge is quite well
defined and generally unbroken, but in
it there sometimes occurs a crevasse or
valley, whose exploration is matter of
much curious interest. Directly off
Point Hueneme, at the entrance to the
Santa Barbara channel, there is found a
remarkable example of one of these sub
marine valleys. Commencing with a
depth of ten fathoms 400 yards from the
beach, it increases to Fifty fathoms in
five-eighths of a mile and then drops
suddenly to 113 fathoms, or 67S feet, il
less than two miles Its general direc-
ton is south, and it is bounded all round
by depths of from twelve to fifteen
fathoms.
Another remarkable example of tn
submarine valley has been discovered,
and to some extent traced out in Mon
terey bay by Commodore James Alden.
The head of this valley is five-eighths of
mile south of the Salinas river, and the
twenty fathom line is only quarter OF
mile off the beach, the depth increas-
ing to fifty fathoms in the next quarter
of mile. AT this distance from shore
the twenty fathom lines are three-eighths
of mile apart. The general direction
of the valley for the next two miles is
southeast, where there is depth of III
fathoms, the fifty fathom lines running
about fye-eighths Of mile apart; thence
the valley runs about west, reaching tia
depth of ITO fathoms in mile and 24d
fathoms in three and one-quarter miles,
with forty-two fathoms less than mile
to the north. The soundings are not
numerous enough to trace its outlines in
deep water, but the indications are foi
ten miles of its length that it runs south
west, with no bottom at 315 fathoms. It
would appear from this description that
this valley is really an enormous canyon
that opens through the shore line ledge
clear out and down into the deep water
of the / 900 fathom belt.
Here again the terms deep and crevasse
are to be taken in their comparative
sense. These submarine valleys Of the
coast line ledge have their dimensions,
it is true, but they sink into utter in
significance beside the abysses which
mark the bed of the great ocean, abysses
which seem to drop clear to Tophet or
Davy Jones' locker. To the east of the
Kurile Islands and Japan there lies a
crescent shaped space Of deep water that
really merits the term. 1t extends from
fifty degrees north latitude to nearly
twenty degrees north latitude, or for
1900 miles, although it is Of no great
breadth. The average depth of this area
is nearly 1900 fathoms-that is, nearly
$4,000 feet This is deep enough in all
conscience, but along its western margin,
and lvino like ditch across the entrance