Encyclopædia Britannica, Ninth Edition/Antarctic Ocean

ANTARCTIC OCEAN, a name that should, strictly speaking, be applied only to the ice-bound sea to the south of the antarctic circle; in practice, however, it is usually vaguely extended so as to include more or less of the cold regions round the south pole, without reference to the circle. As compared with the corresponding Arctic Ocean little is known about this portion of the earth s surface; but it is sufficiently clear that the cold and the dangers to navigation in the southern ocean greatly exceed those of the northern, and that human beings and most other animals cannot, or at least do not, ordinarily subsist within its limits. See Polar Regions.