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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
ANTARCTICA 
ANTARCTICA 
Fig. 1. Approximate areas of vertical, oblique 
and trimetrogon photography 
Fig. 2. Areas considered to be essen 
tially featureless. 
East Antarctica with its ancient crystalline shield is almost completely cover 
ed by the continental ice sheet. Only a fairly narrow zone of mountain peaks 
and ice-free areas occurs along the coast, broken in some areas by deep fiords 
and valleys. West Antarctica, on the other hand, is a region of mountain 
ranges which occur both along the coast and inland as detached marginal 
forms. Isolated peaks and smaller ranges rise as islands above the ice plateau. 
An inventory of mapworthy areas has been made from a photo interpretation 
study of trimetrogon exploratory photography flown between 1946 and 1962, 
supported by other information such as seismic surveys for measuring thick 
ness of the ice [Thiel 1961]. It was determined that about 2 million square 
miles of the Antarctic surface could be considered to contain mapworthy fea 
tures. Of the 4,000,000 square miles of essentially featureless Antarctic surface 
approximately 800,000 square miles are in West Antarctica and 3,200,000 
square miles are in East Antarctica (fig. 2). 
While it is apparent that a large part of the Antarctic ice sheet, particularly 
the high plateaus of the eastern half, will consist of rolling plains of featureless 
surface, this does not necessarily mean a complete absence of features. Fig. 3 
shows a series of parallel-drawn lines in the snow, vanishing in the horizon. This 
new phenomenon, located in the eastern portion of the “featureless” polar 
plateau, emphasizes that our knowledge of the properties of the snow cover is 
meager. 
Mapping crevassed areas 
Crevasses and crevassed areas are among the most important ice surface 
features. A crevasse is a fissure or rift in glaciers, shelf-ice, or other land-ice