The Wilmington morning star., 1947-07-13

+ Four miles below wafer leVel,
i his vast expanse of soft and
sticky sediment has not been see
by man. but i is important to
him. The sea bed covers nearly
&hree-fourths Of the earth S
surface. Buried in its murkiness
are secrets of the earth's past,
mo perhaps of it's future.
Just as trees record their age
" an evar-increasing number OF
.inss. the earth places clues to
is history in the layers OF sed1-
nent when have been slowly de-
posted through geologic time.
Collecting samples OF this sedl'
nent for laboratory study is one
IF the tasks of a scientific expedl
ion to the Mid-Atlantic ridge
sponsored jointly by the National
Geographic society, Columbia
university, and the Woods H o e
Mass Oceanographic Institution.
The expedition, leaving WOODS
Hole on July Is in the research
ship Atlantis, will survey a 5o,0oo-
square-mile area Of the Atlantic
about eouidistant e e
Bermuda and the Azores. A mile
Or more below the surface
stretches the Ridge, a narrow S
,haoed cnain of undersea noun
aims. P%aralleling the coasts OF
North and South America, Europe
and Africa, the range extends IN
! nearly continuous line from Ice
and almost to Antarctica.
4 This Mid-Atlantic Ridge is one
If the prominent features OF the
sarth's crust. It's peaks rise two
miles or so from the ocean floor.
Some even break the surface OF
he water to form the Azores,
Rochedos Sac Pauio (St. Paul
Island), Ascension, and Tristan da
Iunha.
How and when the Mid-Atlantic
Ridge was formed r questions
% which geologists and ocean-
ographers are seeking the answer.
some scientists believe that it was
eft behind when the continents OF
..he Western Hemisphere broke
away from Europe and Asia.
Others have suggested that it rep
resents a pushing-together rather
than a separation of land.
Before the solution can be
reached, scientists must accumu-
late a mas of evidence about the
topography Of the Ridge, the
nature and depth of its sedimen-
tary covering. and the character
IF it's rock. The expedition aboard
the Atlantis hopes to acquire some
of this basic Information.
The depth CT a portion of the
Ridge ard its flanks will be
measured by echo-sounding. A
sound wave produced as the ship
travels to the ocean floor and then
is reflected back 10 the ship. The
exact time required for the round
trip is recorded, and the distance
to the bottom is calculated from
the velocity Of sound in the water.
The resulting chart will show
The relative position of peaks ana
depressions. Previous soundings
along the western flank have
recorded extremely rugged top
ography. Should there happen to
be any submarine canyons in the
region, they would become evident
from the graph. These steep-Wall-
ed burrows have been found IN
coastal shelves around the world,
out not in mid-ocean. Their origin
whether by submarine or S b.
aerial erosion, glacial action, sub
marine springs. OF earthquake
waves is still unsolved.
To collect samples of the sedi-
ment on the ocean bottom, tn e
scientists will lower steel tubes 10
End Is feet long over the side OF
the Atlantis. Heavy weights drive
TIE tubes into the mud, and a
cross section Of the sediment is
trapped. These cores" are
brought TO the surface and dried,
with the original layering intact.
The procedure is somewhat like
plugging a watermelon to see how
ripe and sweet it is.
In the ooze r the residue Of
minute seaWeeds and the skele-
tons of microscopic animals which
s,..in IN The surface levels Of the
ocean. After these organisms die