Evening star., 1954-04-19
Antarctic Expedition
Surveys Ice Lund'
George VI Shelf Has
Fontustic Features
By Thomos R. Henry

A strange "ice land" more than
5000 square miles in area. cuts ap-
proximately $50 miles into the noun
tains Of the Antarctic Continent at the
base Of the fingerlike Palmer Peninsula.
This is the George vi shelf, named
for the late British king, which hitherto
has been barely noted on maps Of the
South Polar region. It is weird white
country. the Antarctic land Of lakes.
During the brief summer it is full Of
deep lakes. some more than mile long.
fed by the snow melting on the barren
mountain rocks.
The region Is described by DR..
Robert L. Nichols of Tufts College in q
report on the geological discoveries Of
the 1949 Antarctic expedition of Comdr.
Finn Rome. just issued by the Office
OF Naval Research. Descriptions of the
fantastic natural features of the area
are based on observations made on
sledge expeditions by Comdr. Rome
himself and by members Of the British
Falkland Islands survey mission in the
same area.
This is permanent ice area at the
head OF George vi Sound. southern
extension Of Marguerite Bay. probably
partly floating like platform on water
and partly grounded at the foot of the
mountains which is comparable to the
great Ross shelf to the southeast which
has been described as one of the FORE
most natural wonders of the world.
Ice Is Rock
On such a shelf, ice is crock" and
duplicates the formations found on
land, even to low mountain ranges.
Shelves are considered part Of the
Continent. rather than of the sea. The
George vi shelf, being further north
and Of different confguration with
respect to the surrounding land, nat
urally presents features not found on
the Ross shelf.
Notable in the scenery, DR.. Nichols
reports. are the many ''ice volcanoes"
or calderas, the origin of which remain
unexplained. These are bowl-shaped
depresSions, about mile in diameter,
with gentle outer slopes rising above
the shelf level but lined on the inside
with nearly vertical cliffs scores of
feet high. At the bottom are found ice
mounds and stacks of ice. Superficially
they are very much like the collapsed
This shelf is, for the most part, q
smooth. almost featureless surface with
few OF the crevasses which constitute
one OF the greater dangers of Antarctic
travel. At one spot. however, is q hill.
or nunatak, more than 1000 feet high.
East and northeast of this nunatak
is an area Of ice hills, all heavily
crevaSSed.
A somewhat similar region is found
on the Ross shelf and Is called Roose-
velt Island, but is probably group Of
small, rocky islands just offshore and
completely buried beneath the ice.
Sea Water Beneath.
There is sea water under considera-
BILE part OF the shelf. DR.. Nichols be-
lleveS, for salt water is found in a
crevasS many miles from the sea front.
The seaward face consists of nearly
continuous ice cliffs 80 to 40 feet high,
comparable on smaller scale to the
majestic Ross barrier to the southwark,
into which juts the open water Bay Of
Whales. DR.. Nichols assumed that
about IS per cent of the shelf is above
sea level and that the ice runs from 200
to about 270 feet thick. =
A considerable tide runs under part
OF this ice, observations show, but the
fiat surface at considerable distances
from the barrier is more than $50 feet
above sea level On It's land sides the
ice region Is margined by glaciers, steep
snow slopes and stark cliffs of bare
rock. Glaciers, sometimes called "ice
rivers" apparently actually flow
through it into George Sound, piling
the ice through which they flow into
deeply crevassed and hummocky areas.
Riffs 80 feet deep and up to half mile
wide are formed.
The region in summer might be COM
pared to an Ice oasis with its succession
OF great lakes. feature not found on
the Ross shelf. Although the King
George shelf is somewhat further north,
the temperature of the two ice lands
does not differ materially and the
thermometer recording air tempera-
ture seldom rises above the freezing
point Quite different. however. is the
phenomenon of melting by radiant
energy from the sun heating an OBJ
ject without materially affecting tenn
peratures, so that on a zero midsummer
night a person may be quite comfort
able without an overcoat in the bril-
liant Antarctic sunshine from the
cloudleSs sky.
Melt-Water Lakes
'Melt-water enters these lakes from
the snow and rocks above" DR.. Nichols
says, land streams run from them into
nearby crevasses. The melt-water
comes from the highlands which border
the sound and from the melting Of
upper layers of the shelf ice. Radiant
energy from the sun rather than the
thermal energy in the atmosphere Ia
probably responsible for most of the
melting. These lakes freeze solid dur
ing the cold season."