From the NSF press release:
Here’s a cool website with satellite images of the iceberg: http://uwamrc.ssec.wisc.edu/amrc/iceberg.html
Hope I’m not introducing a bit od pseudoscience, but didn’t someone find a map of the world (from the time of Ptolemy) which showed the antartic continent free of ice??
Is it possible that the icecap now over Antarctica, was deposited fairly recently? I seem to read that the Russian scientists drilling at Vostok station found green twigs and leaves-were these ever radiocarbon dated?
egkelly, the map you refer to is called the Piri Reis map. It is the pride and joy of Erik von Daniken and friends, who like to use it as evidence that the aliens were providing geographic information us humans in the not-too-distant past; the idea is that only aliens would have had the technology to penetrate the ice cover to map land. IIRC, the map dates from the 1500’s, and is supposedly a copy of an earlier map. I don’t know what the latest thinking is on this thing.
With respect to the age of the ice sheets on Antartica: The East Antarctic ice sheet began to form approximately 36 million years ago, after Antarctica rifted and moved southward from the southern margin of Australia and the circumpolar current was born (thus isolating Antarctica climatically). The West Antarctic ice sheet developed later, but still has been pretty stable since about 12-15 million years ago. Maximum ice thickness near the center of the content is IIRC about 3 miles. The elevation of the ice sheet at its thickest point is not 3 miles, though, because the weight of the ice has depressed the continental crust beneath it. If all the ice were to melt in the next thousand years, say, much of the land beneath the ice would be flooded, until the crust could rebound (10^3-10^4 years, at least).
The controversy you heard about the age of the West Antarctic ice sheet had to do with the interpretation of some pollen and plant fossils recovered from glacial sediments of the Sirius Group in the McMurdo dry valleys (not ice from Vostok). Some scientists interpreted their finding of Nothofagus (southern beech) remains to indicate that the climte had been considerably warmer in Antarctica just 3 million years ago. Since the implications of such a situation were pretty profound for paleoclimate research, a number of others jumped in to do additional investigations. Ultimately, these new studies found the anomalously young interpretation to be incorrect.
The confusion about the age of the Nothofagus remains stemmed partly from the fact that the original researchers did not realize that the sediments they were studying included re-worked material from much older deposits (sounds like it should be simple to tell, but sometimes it’s actually quite difficult to do). Contributing to the problem was the difficulty in differentiating glacial deposits of different ages, because sedimentologically they are very similar. However, it was eventually shown that the Nothofagus fossils were at least 11 million years old, so there hasn’t been any “recent” warming in Antarctica (certainly not enough for humans to make maps 
).
Um … which directions are “east” and “west” if you’re standing on the south pole? 
Fillet: thanks for the detailed info on Antarctica-you obviously know a lot about that place. I have another question for you-a few years back I read about the scientists who investigated the lakes in the “dry valleys” of Antarctica. They cut holes in the ice, and sent divers down-and in some of them, the water (at the bottom) was something like 75 F! I also recall there was plenty of algal life-do such lakes exist in the high arctic? And, how old are these lakes?
tracer, when you’re at the South pole, longitude is your friend! You can divide Antarctica into east and west using the 0 and 180 deg. lines of longitude; the geologic boundaries of east and west Antarctica coincide more closely with 30 deg. W and 150 deg. E. The little tail (the Antarctic Peninsula) falls on the western side. You can check out the CIA’s map of Antarctica, as well as take a virtual tour of some of the sights, at http://astro.uchicago.edu/cara/vtour/.
egkelly, I’d love to go see the place for myself – what a trip that would be! You heard correctly about some of the peculiar and interesting discoveries made in the dry valley lakes. Gateway Antarctica has a visitor’s introduction to the continent and the environment; if you look under “Lakes, ponds, and pools” you’ll see a nice summary of the types of lakes that exist and what sorts of life might be found in them. I don’t recall offhand seeing a particular age estimate for the dry valley lakes, but they could be several tens of thousands of years old, or perhaps older; it depends on when the ice retreated from the valleys.
To the best of my knowledge, there are no arctic lakes with ecosystems quite like those of the Antarctic dry valleys, although the arctic lakes could certainly support some of the hardier little organisms we have on this planet.
Boy, this is not my day for posting links correctly. The visitor’s introduction to Antarctica can be found here.
Fillet, you can go down there for a visit and get paid, too. Every year when the scientific group leaves a maintainence group moves in to fix up whatever needs fixing.
A cousin went as an assistant to an electrician, he was fresh out of college and had been plugging in lamps and radios for years. Loved it, connected to family and friends by email, sent back fantastic photos.
I can put you or anyone else in touch with him if interested.
Are you driving with your eyes open or are you using The Force? - A. Foley
Fillet,
In your reply for Bricker, you said that the warming trend is no big deal for Mother Nature. I agree. But threats that Mother Nature can shrug off can be deadly to the human race.
I allways tell people who are complaining about the Greens this: They’re not trying to save the world. The world can take care of itself. It’s your ass they’re trying to save.
IIRC(leaving myself some weaseling room) Some scientists are blaming the great extinction before last. Not the dinosaur killer. But the one that wiped out the Therapsis. Anyway that it was caused by the supercontinent of Pangea. Without cooling coastlines, the tempurature went up drasticly. over 90% of the land and sea species were lost.
Do we want to join them?
Obviously this is theory(another possible out). But scary theory.
The Antartic stuff is good, so you probably have heard of this too.
Also, did I learn somewhere that the Sahara was enlarged by overgrazing?
___________________________________Salaam
Brave, Brave, Sir Robin -Monty Python
Suppose that global warming is real? Perhaps it might be a major benefit to mankind. So Florida gets submerged-well, no big loss; but, all of a sudden, all of Arctic Canada becomes inhabitable! There’s a lot of useless land up there which is ready and waiting-seems to me Greenland would be nicer with a climate like present-day S. Carolina! (and, no snake handlers!). I’m off to purchase some land in the NW Territories (or whatever the Iniut call it these days!)
On one Discovery Channel show several years ago, the narrator claimed that the mail rise in sea level during a period of global warming will be due not so much to the melting polar ice as to the expanding of the liquid oceans as they get warmer.
Any truth to this? How much bigger of a factor (10-fold? 100-fold?) will ocean expansion be on rising coastlines than melting polar ice?