Vacation to Mars: Antarctica's Dry Valleys

Image credit: 
Mike White

Most of Antarctica has about 2 1/2 miles of ice covering it, and that cold, white wasteland is what most people picture when they think of our south pole. But as I discovered when I posted about its mysterious Blood Falls, there is a series of dry valleys in Antarctica, about 4,000 kilometers square, that have no ice on them at all. The world's harshest desert, the moisture is sucked from the dry valleys by a rain shadow effect -- winds rushing over them at speeds up to 200/mph -- that leave this bizarre and fascinating landscape, much closer to that of Mars than the rest of our planet, open to exploration.

Lacking the resources (or cojones) to go there myself, these photos are by scientists and researchers who've been there, and are included as part of galleries on the McMurdo Dry Valleys Management Area website.

The Valleys have been carved out by glaciers that have retreated, exposing valley floors and walls that typically have a top layer of boulders, gravel and pebbles, which are weathered and wind-sorted. Lower layers are largely cemented together by ice. Unusual surface deposits include marine sediments, ash, and sand dunes like this one:

sand - chris kannen
Photo by Chris Kannen

Another thing you wouldn't expect to find in the coldest place on Earth? Running water. In the summer, bodies of water unfreeze enough to make water flow, like the continent's largest and longest river, the Onyx, which is fed exclusively by glacial melt. This little stream is frozen, but you get the picture:

stream - sean fitzsimmons
Photo by Sean Fitzimmons

However, there are some bodies of water in the dry valleys -- mostly small, hypersaline ponds -- that never freeze. Imagine how strange it would be to find, in weather 100 degrees below zero (and in the depths of a months-long night) this little patch of salty liquid, known as Don Juan Pond:

don juan pond - malcom mcleod
Photo by Malcom McLeod

It looks so dry and calm in most of these pictures, it's hard to comprehend just how arid and cold it really gets there. Here are a few pictures that might help -- a dead seal, frozen solid and mummified, absolutely dehydrated.
mummified seal - chris kannen
Photo by Chris Kannen

And some very cold-looking rocks!
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Photo by Andris Apse

Then there are places that look like they might as well be on the moon, like these pillars of dolerite in the Kennar Valley. (They remind me of the tufa rock formations in California.)
pillars of dolerite - gretchen williams
Photo by Gretchen Williams

Below is a volcanic "labyrinth," a very special formation of basalt, which geologist Edmond Mathez describes this way:

The dikes and sills of the Dry Valleys are the remnants of a kind of plumbing system through which magma worked its way to the surface in a series of eruptions about 180 million years ago. Volcanic plumbing systems are rarely exposed at the surface. The reason is simply that around active volcanoes, lava covers everything. Exposed to view in various parts of the Dry Valleys, however, is a vertical slice of the dikes and sills immediately beneath the lavas, which cuts across layers of rock two and a half miles thick. Hence along the valley walls, geologists can see much deeper into the volcanic plumbing than they can almost anywhere else.

labyrinth - peter rejcek
Photo by Peter Rejcek

It's not just scientists that visit the dry valleys, though. Small groups of tourists are allowed to helicopter in from the Ross Sea, to a specially designated area near the Canada glacier -- so if you're loaded and ready to freeze your buns off, that sounds like fun. There's also this guy, a painter named Nigel Brown, who won a fellowship to come and paint in the valleys. Look, he made a weird painting of Blood Falls:

blood falls painter - tim higham
Photo by Tim Higham

If you've ever dreamed about visiting an alien world, this is probably as close as any of us will be able to get.

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February 3, 2010 - 6:38am
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