Thursday, November 23, 2006

The Dry Valleys

Half of Lake Hoare Camp (Canada glacier in the background)

I have finally arrived at my field site, the place I will live and work until February. Our time will be split between Lake Hoare Camp (where I am now) and F6 camp on Lake Fryxell. Lake Hoare Camp is a pretty posh field camp as far as field camps go, and even has a camp manager who cooks dinner for us! We will make it to F6 in a few days. My field area of study (and both Lake Hoare Camp and F6 camp) is located in the Dry Valleys, a rare area ofrelatively ice free land that is effectively a cold desert. I will be working predominantly in the Taylor Valley, the southernmost dry valley.
The Taylor Valley (Lake Hoare in the foreground)
The dry valleys are so named because there is no snow or ice on the ground surface and there is extremely low air humidity (even lower than the rest of Antarctica). Weather systems that deliver anything but high winds are rare because of the protection provided by the Transantarctic Mountains and the direction of the prevailing winds. The winds in the valleys are also unique because even though they are coming off of the continental ice sheet, they can be very warm. Researchers have discovered that as the air descends into the valleys off of the ice sheet, it is compressed, the act of which releases heat. These warm winds and weather protection often make the dry valleys 10-15 degrees F warmer than McMurdo. Thank goodness!

Because of its stark and desolate landscape, scientists often compare this region to the surface of Mars. Instead of ice, loose gravelly material that comes from the end moraines of the valley glaciers makes up the substrate. This landscape is also unique because running water is very rare on the surface of Antarctica. Here, as summer temperatures rise to just above freezing and the 24 hour sunlight begins to melt the glaciers, streams start to run. It is this melting season that my group is interested in.

There are very few macroorganisms in the valleys, but a surprising amount of life is hidden in the streams and soils. Some examples of organisms are: stream algae, nematodes, moss, plankton, bacteria and other microorganisms called tardigrades and rotifers. In the winter, most of these organisms exist in a freeze-dried state calledanhydrobiosis. When the water begins to run in the summer months, they spring back to life within days or weeks.

The valleys are so sensitive to human impact that you can find footprints made by people 60 years ago. Earlier expeditions were careful, but often contaminated the land with trash or fuel. Science groups have dug up trash heaps from 1945 that still haven't decomposedat all. Modern environmental regulations were established to avoid contamination in an environment where any pollution would last for extremely long periods of time. Now, all fuel is delivered to the valleys in 55 gallon drums at the start of the season, and even aspill of a teaspoon has to be reported and cleaned up by the spill response team. All used water (even for washing hands) and human waste is put in barrels and flown out at the end of the season. The dry valleys were designated as an Antarctic Specially Managed Area in 2004. This designation means that scientists from the US, New Zealand and Italy as well as tourists work together toward stricter environmental standards established by the agreement.

View from my tent at Lake Hoare Camp


George said...


Is the Canada glacier relatively stationary, or not. From the perspective of the photo, I would worry about having the glacier advance over me during the sleeping period. Outlandish, I know, but the landscape is surreal!


Emily said...

The glacier is relatively stationary, especially in the human time scale. Geologigcally, probably not, but it certainly does not "surge" like alpine glaciers do.
The toe does not calve either- it's stable enough to ice climb up.