The Australian flag is raised over the Mawson base, named é ; x
noted Australian aeniorer: The base is on MacRobertson Land, Antarctic territory claimed

by Australia.

Fae a8

for Sir Douglas Mawson,

The sixth

continent

Scientists from many lands are exploring
the world’s most forbidding and least known land

THe polar regions, both north
and south, are of excep-
tional interest to science.

These areas influence the
climate of the whole world,
and in them are to be found
the poles of the earth’s axis
and the magnetic poles, where
the earth’s* magnetic merid-
jians come together.

But unlike the North Pole,
which is almost the centre of
the great frozen Arctic Ocean,
the South Pole is on the con-
tinent of Antarctica, which
covers a great area—approxi-
mately five million square
miles — all within the Antarc-
tic Circle.

“The most distinctive feature
of the continent is that it is
covered by an imense sheet
of ice. Under its own weight
the ice is sliding towards the
coasts on all sides.

But in the past this was not
the case: finds of animal and
vegetable fossils indicate that
tropical and ‘warm climates
once existed there. “a

The Ross and Weddell Seas,
cutting deep into the contin-
ent from two opposite sides,
ate of great geological signifi-
cance,

The seas seem to divide the

By DMITRI SHCHERBAKOV

continent in two — the east-
ern, occupying about two-
thirds of its area and the wes-
tern. =

The eastern part is made up
of very ancient rocks, covered
in place by almost horizontal
layers of younger and some-
times coal-bearing rocks. This
is a highly elevated and mark-
edly broken-up plateau, in
geological structure not unlike
South Africa and Central Aus-
tralia.

The western part is made up
of a number of great moun-

tain chains running along the -

Pacific Ocean coast. They are
considered a continuation of
the South American Andes
emerging later in New Zea-
land.

Between “East” and “West”
lies a part of the continent
which has subsisted as a re-
sult of faults in the earth’s
crust. The geological process-
es which took. place here long
ago determined the formation
of the Ross and Weddell Seas.

*

So far, however, no one
knows what ‘lies: between the
seas — dry land or a wide arm
of the sea.

Today all this expanse is
covered by a great blanket of
8 Ty = eaeegs

Even the aerial photographs
taken by the American expe-
dition could not provide an
answer to this question, which
remains one of the great
riddles of Antarctica.

The ice barrier frequently
merges with the continent’s
coastline and this for a long
time deceived navigators,

From the high mountain
valleys near the Pole “flow”
great glaciers, scores of miles
wide and hundreds long. Their
long “tongues” reach far out
to sea.

It is from such ice that the
famous Ross Barrier is form-
ed.

The Queen Maude range
stretches for about 1,500 miles
not far from the South Pole.
According to the Byrd expedi-
tion, its average height is in
the region of 13,000 feet. Some
peaks reach more than 16,000

feet.
*

In the central part of the
range over which Admiral
Richard Byrd flew in 1947 a
great valley, free from ice,
was discovered.

Its slopes are made. up of
’ pink, red and purple rocks,

amony which coal strata are

prominent. Here is to be found
one of the world’s largest coal
deposits.

But this is not the only
place in Antarctica where
land is to be seen free of ice.

During flights carried out
by the American expedition,
the investigators were amazed
to discover extensive. areas
free of ice in many regions,
with glittering lakes of blue
or red water.

Seaplanes landed on several
of these lakes. Members of
their crews even took the risk
of swimming in one, The water
proved to be comparatively
warm and the airmen were
able to collect a variety of
mosses, _ lichens and water
plants.

The origin of these myster-
ious oases has still not been
firmly established.

It is possible that they ap-
peared as a result of volcanic
activity, but the possibility of
coal fires capable not only of
dispersing the ice but also of
fusing the mineral layers is
not to be excluded.

*

Along the coast of Victoria
Land lie a group of volcanoes,
which may be included among
the largest in the world.

The volcanoes Terror and
Erebus reach a height of 14,000
feet.

The crater of the still active
Erebus has a diameter of more
than half a mile and a depth
of more than 1,000 feet.

Erebus emits a great cloud
of gases mixed with ash and
tinted red with the reflection
of the molten lava.

Each new aerial expedition
discovers some new mountain
range, bays or glaciers in this
great continent.

In Marie Byrd Land a peak
was discovered. and _ photo-
graphed. This peak is at pres-
ent the highest known in Ant-
arctica — 23,600 feet above
sea level.

The present Soviet expedi-
tion, which has been allocated
the least explored sector of
Antarctica in its eastern part
will undoubtedly encounter
hitherto unknown ranges.

What is Antarctica’s icecap
and what is its probable
depth?

It flows down on all sides
from a range which may be
considered to run _ parallel
with the Pacific. Ocean coast.
The height of the ice range
exceeds 10,000 feet.

Several observations indi-
cate that the depth of the ice
overlaying the buried rock
strata varies within fairly
wide limits: from a few score
to more than 6,000 feet.

If it is taken into account
that the area of ice on the
continent is one and a half
times greater than that of the
United States and seven times
greater than the ice-covered
area of Greenland, then fan-
tastic figures for the amount
of ice are obtained.

Were all the ice in Antarc-
tica to melt, the level of the
oceans of the world would be
raised by 50 to 60 feet.

But the latest figures indi-
cate. a considerably greater
average depth of ice. The data
obtained by the Norwegian-
British-Swedish expedition in

Queen Maude Land area in
1949-52 is particularly interest-
ing.

To measure the depth of the
ice this expedition used the
seismoacoustic method. This is
based on the determination
of the’ speed of vibrations
transmitted through the ice
layer and ‘:‘bounced” back
by the rock layers.

By calculations, it was pos-
sible to define the depth at
which the earth lay beneath
the ice.

Members of the expedition
drafied the profile from the
.coast to a depth of some 375
miles into the interior. It prov-
ed that the mass of ice in fact
obliterates the very complex
relief of the ground beneath,
which is broken up and made
up of separate peaks, plateaus
ranges and valleys.

According to these measure-
ments, the thickness of the
masses of ice in places reach-
ed 7200 feet. Towalrds the
coast they become thinner and
give place to what is known
as barrier or shelf ice,

But in the comparatively
recent past the ice was even
thicker and reached consid-
erably further out to sea than
it does now. Scientists believe
that the thickness of the ice
was some 1,000 feet greater
than it is today. The Antarc-
tic ice is now on the retreat.

Most interesting of all is
the fact that in Antarctica, as
in Northern Europe and Asia,
there were clearly several Ice
Ages, or, in other words, sev-
eral stages in the advance and
retreat of the ice.

Undersea deposits are the
best demonstration of this.
They are obtained at some
distance from the shore with
the aid of vertical drilling with
hollow tubes which are forc-
ed down into the sea-bed.

In the columns of earth
thus brought to the surface,
the fine-grain material is seen
to be clearly stratified with
the coarse-grained. This strati-
fication indicates variations
in Antarctica’s climate.

Another interesting peculi-
arity of Antarctica is that its
continental shelf, or its under-
water part, which usually ends
abruptly with a steep slope
going into the ocean, lies con-
siderably deeper under the
water than do those of Eur-
ope or the North American
continent, for example.

Scientists who have studied
this question tend to be of the
opinion that the abnormal
depth of the continental shelf
is a consequence of the great
weight of ice on the contin-
ent, which has “pushed” it
down into the earth’s crust.

True, this weight is now
considerably less than hither-
to. But the reverse movement
of the earth — its rising up —
is extremely slow.

Therefore the third riddle
is the reason for the existence
of so great an ice layer and
the study of the changes in
it

The solution of this riddle
will undoubtedly throw light
upon the problem of the great
Ice Ages which long ago grip-
ped a considerable part of
Northern Europe and Asia and
also North America.

FEBRUARY 22, 1957 — PACIFIC TRIBUNE—PAGE 11