THE GLACIERS AND THE ICE SHEET 413 
course there may be catastrophic years. We know that 
icebergs are very plentiful in some years in the Southern 
Ocean. This last summer our Glacier Tongue broke away 
after remaining for many years. 
VII. Mainland Glaciers. — There is very little evidence 
of large motion. David says the Nansen Glacier presses 
out the sea ice ; but quite probably it is the other way, 
and due to the sea ice pressing against the Glacier Tongue. 
The movement of the glaciers is a measure of the pressure 
behind ; they are, however, so cold in these regions that 
their movement is sluggish compared with those in 
temperate climes. 
I do not think there is anything like 13 inches annual 
snowfall on the Ice Plateau. If there is recession along 
the coast, the same must obtain on the great Ice Plateau. 
The high level moraines decrease in height above the 
present surface of the ice, the debris being 2000 feet up 
near the coast and only 200 feet above near the plateau. 
However, the Beardmore from its great crevasses seems to 
show extra movement. 
VIII. The Inland Ice Sheet. — All our data are 
hypothetical — we are erecting an edifice of theoretical 
bricks ! We may give it the area of two-thirds of the 
circle drawn with a radius of 1200 miles. 
There seems to be a descent from 9000 feet at the Pole 
to 2000 near the edge, and then a rapid fall at the sea line. 
We may surmise 50 to 100 yards movement per annum 
across the edge of the Plateau, with a thickness of 700 or 
800 feet ; but all this is merely a fine effort of the 
imagination ! 
