788 
MR J. M. WORDIF, ON 
in the north-west. These terraces are shown diagrammatically on the accompanying 
figure. The slope from one terrace to another is of course much distorted ; if drawn 
to scale it would be almost imperceptible, as it works out on the average at only 
1 in 200. 
On the east coast of Graham Land the Charcot Expeditions have shown the shelf 
there to be at least one hundred miles broad and of similar depth to what it is in 
the Weddell Sea. In the past indeed the Antarctic continental shelf has aroused 
considerable interest by reason of its depth being double the average depth of the 
shelf round the other continents — 200-250 as against 100 fathoms. Philippi, 
commenting on this, thought it might be due to planing down by ice during the 
once greater extent of the Antarctic ice-cap. Nordenskjold, on the other hand, 
thinks there may be some connection between the existence of the great Antarctic 
ice-cap and a resulting land submergence. The terraced structure, which the 
Endurance observations show, at once disproves Philippi’s' idea. These features, 
however, can be explained by faulting ; * and it may therefore be the case that the 
deep Antarctic shelf here and elsewhere is the result of earth movement of some sort 
rather than of erosion. 
(5) The slope of the continental edge as deduced from the Endurance figures is 
1 in 62. This result is certainly misleading ; for unfortunately the edge was crossed 
in a three-day blizzard at the beginning of August 1915, when the ship was in 
considerable danger and sounding therefore of secondary importance. There is an 
interval of forty miles or more in which to place the edge ; the 185-fathom sounding 
is just over sixty sea-miles from a depth of 1146 fathoms. The sounding of 370 
fathoms, no bottom, is of practically no value, as it is only ten miles, from 1146 
fathoms. That the edge is much steeper than 1 in 62 is more than likely, judged by the 
paired soundings of other expeditions. The steepest slope recorded by any Antarctic 
expedition is 1 in 17, and the average 1 in 26 ; the real slopes, moreover, will 
probably be a trifle steeper, as the chance that a ship crossed the edge at right angles 
is small. The Endurance figure should therefore be put aside. 
Sounding 
on Shelf. 
Sounding in 
Deep Water. 
Distance 
Apart in 
Sea-miles. 
Slope. 
Belgica 
279 
1476 
25 
1 in 29 
Gauss .... 
209 
1267 
18 
1 „ 17 
Scotia . . . . 
159 
1950 
45 
1 „ 25 
Deutschland . 
305 
820 
18 
1 „ 35 
Endurance . 
185 
1146 
60 
1 „ 62 
(6) In the forefront of all bathymetrical work in the American sector of Antarctica 
is the question of the one-time relationship to each other of the various island groups 
which border the Weddell Sea to the north. On this important point, however, the 
* Nordenskjold states that Bransfield Strait is due to faulting. 
