Andrew Grebneff writes,

> And you raise a good point. Some oceans are fairly well-defined eg Black
Sea, Red, Mediterranean and Arctic..

> The Pacific & Atlantic can logically be separated by a north-south line
drawn between the southernmost points of South America & Africa and
Antarctica; where a line betweer the Pacific & Indian should fit is a bit
more problematic... perhaps Tasmania?

> But where do you draw logical boundaries for the "Antarctic Ocean"? This
so-called entity is really arbitrary, and technically speaking there is no
such ocean, merely the south Pacific, Atlantic & Indian.

Well, but if you define an ocean as a body of water, not a basin filled with
water, then the 'Southern' or 'Antarctic Ocean' is a body of water that
encircles Antarctica and consists of very cold water that is slightly
saltier than the rest of the world ocean, because part of the water is
removed by freezing while most of the salt remains dissolved. Its surface is
also considerably richer in oxygen than the world ocean because cold water
can dissolve more oxygen than warm water, and the whole mass of water tends
to descend because salty water is relatively heavy -- carrying that nice
oxygen down to help keep the abyss sweet.* All of which give the water a
distinctive 'Southern Ocean' biota. But as a New Zealand scholar you know
this already, eh! Just checking to see if the rest of us know, eh?

Andrew K. Rindsberg
Geological Survey of Alabama

*This reminds me of an explanation that I once read in a 19th-century
theological treatise on geology. The author said that the oceans were
designed to be salty in order to preserve their contents -- a sort of giant,
open pickle barrel. Though I can't agree with this nonsense, it certainly
made good reading. Unfortunately, I don't remember the author or title.