Evening star., 1954-05-09
Antarctic Ice Shows
Signs Of Retreotinq
Melting Leeds to Belief
Lond Moy Come Alive
By Thomos R. Henry


BY Thomos R. Henry
The great ice sheet which almost
completely covers the Antarctic cont.
nent is retreating, in some places at 0
rate Of more than three miles year.
If this rate is general and progressive,
very large areas of land surface. pre-
Sumably ice-covered for at least 20 mil
lion years, will be laid bare In a few
centuries and the edges Of the dead con-
tinent can start coming to life.
These observations are described by
DR.. Robert L. Nichols of Tufts College.
by Comdr. Finn Rome. in a report on
the geology Of the region which has
lust been issued by the Office of Naval
Research. Most notable Of these OBJ
servations we're those of the retreat in
land of the 5,000-square- King
George ice shelf at the foot of Marquee
rite Bay, where the expedition was
based. There is, for example. the emer-
gence of the Eklund Islands.
In 1910 Comdr. Rome, then in COM
mand Of the northern group Of the Byrd
expedition. discovered rocky hill about
80 miles inland from the seaward edge
of the shelf which was named after DR..
Carl Eklund of the Fish and Wild Life
administration, a member of the party.
Five years ago DR.. v. E. Fuchs of the
British Falkland Island Dependencies
Survey found in the same area 10 is
lands instead of one, Of which Eklund
Island was the largest. Comdr. Rome
had found them embedded in shelf ice.
DR.. Fuchs found them surrounded by
the far different sea ice. in places not
more than two inches thick. Thus q
new archipelago Is added to world maps.
Notes Ice Moving Back.
Comdr. Rome himself new over the
area and noted that the shelf Ice had
moved back q roughly estimated IS
miles from the time he last had seen
it, seven years before. It still cannot
be determined, DR.. Nichols says.
whether the shelf ice actually is getting
thinner or just melting inland from the
seaward face. II the former is the case,
the retreat could be expected to be
progressively faster.
Other evidence Of ice retreat in rel-
atively recent years, although 1t has
not been directly observed, is afforded
by the Terra Firna Islands, an archi-
pelago in Marguerite Bay at least IS
miles from the Ross Shelf barrier. On
the largest of these islands is a fiat
area of several acres covered with
boulders-a formation known in Ant
arctic Technology as "felsenmeer"
or stone lake. Study of the boulders
shows that they must have been carried
from the mainland mountains by gla-
ciers in a relatively recent time, since
they show no signs of weathering. but
of having been underneath Ice for q
long while.
They must have been carried to their
present position, DR.. Nichols concludes.
on very thick glaciers. He deduces that
when they were deposited the ice must
have been at least 500 feet thick, must
have extended for at least five miles
farther out to sea and, since it grows
thicker towards the land. have been at
least 1000 feet thick at the present
edge of the ice shelf. There it now is
less than so feet thick. This whole re-
treat may we'll have taken place in less
than a century. Quite similar evidence
is found on other islands in the bay.
base camp of the Rome expedition
was set up.
Land Believed Rising.
One of the most convincing phe-
nomena found by DR.. Nichols was that
of elevated beaches" rock strewn
areas sometimes of great extent. which
obviously were once at sea level but
Lox 1atraofnd inIQn0
so feet or more above sea level. The
most plausible explanation Tor these
is that the land itself has risen as 1t
has been relieved of the weight OF
several thousand feet of ice. Much
could be learned Of the progress ana
direction of ice retreat he believes. oy
a comprehensive survey OF these
beaches.
At the mouth of Marguerite Bay
stands one of the largest OF the Ant
arctic islands, Alexander the First
Land. discovered by Russian Ant
arctic expedition in 1920 and the basis
for present Russian claims for South
Polar lands. It is traversed by three or
four mile high mountain ranges and
is known chiefly by observations from
the air.
Here. DR.. Nichols believes, the ele-
waited beaches would give the best
evidence Of ice retreat. Early Russian
descriptions are quite vague but the
mountainous certainly protruded high
above the ice more than a century ago
and their slopes could be used as yard
sticks of the extent Of deglaciation.
The phenomena admittedly may be
peculiar to this somewhat sheltered
part Of the Antarctic. Whether the
great Ross shelf further to the south.
east is retreating, standing still or
advancing has been subject Of consider
able debate.
In some years the ice seems to ad.
vance little and in some years to re-
treat To determine whether there is
an advance or retreat over an extended
period is almost impossible.