Wednesday, April 19, 2006
Tuesday night, my wife and I saw The March of the Penguins, the famous documentary on the Emperor penguin, which I recommend. (The movie -- not the bird!) By coincidence, I received an email about Antarctica the next morning from my friend Adrian Hester, who is fascinated by polar exploration. Being in a time crunch and finding the email very interesting, I got his permission to essentially lift it for a blog post.
Here it is with some minor editing.
As you've probably divined by now, I love reading books about Arctic and Antarctic exploration. Today we got in a real treat at the bookstore, an encyclopedia of Antarctica published by the New Zealand agency in charge of their Antarctic activities.
... The most interesting things in it ... were the bits about saline lakes and subglacial lakes. Once I got off work and ate dinner I came straight to campus to read more about them. This is one that was discovered after the book was published, I think.
The most striking one, however, is Lake Vanda. It has twelve distinct layers differing in salinity and temperature, and the bottom averages about 77 degrees F when the surface is at freezing because of the peculiar way it freezes at the surface: The water freezes downwards and evaporates off the top, causing vertical ice tunnels through which sunlight is focused into the depths, trapping the heat underneath.
Another lake, Don Juan Pond, is so saline it contains 1 kg of salts for every 2 kgs of water, and contains so much calcium chlorate that all but the heaviest winds don't stir up more than tiny ripples on the surface.
Around it are deposits of antarcticite, which is largely calcium chlorate.
And the biggest of the subglacial lakes is Lake Vostok, which might have been isolated from the rest of the world by 2 1/2 miles of ice for half a million years or more.