Camping - Dry Valleys

The temperature rises for a few weeks in the summer to start to melt some of the glacial ice entering the Dry Valleys, this feeds freshwater streams that feed into lakes at the bottom of the valleys. These lakes are frozen above, but below the ice colonies of bacteria and phytoplankton are supported by temperatures that are warmed by the ice acting as a lens passing through the fleeting summer sunlight.

Despite the apparent sterility of the environment there is life in the Dry Valleys though not terribly advanced life. The water of the lakes might at first appear to be as pure as any water on the planet could be, but this is not the case as discovered by Scott and his men a hundred years ago.

They drank water from lake Chad that had no taste and no smell that they thought like the vast majority of water available in Antarctica to be amongst the cleanest and purest on earth, however it gave them dreadful diarrhoea leading to the use of large amounts of toilet paper that went by the brand name of "Chad" - hence the naming of the lake.

What had caused their illness was toxins released by one of the most primitive organisms on the planet - Cyanobacteria, a photosynthetic bacteria that may be seen around seasonal meltwater streams and lakes in the Dry Valleys looking not unlike a small cowpat. The Cyanobacteria is brown to protect it against high levels of ultraviolet light.

There are other oddities in the region of the Dry Valleys too, one of which is "Blood Falls" first discovered by Griffith Taylor on Scott's Terra Nova expedition in 1911 who was the first to explore the valley which is named after him.

As well as being striking in appearance, Blood Falls (picture below) has an unusual cause. The reddish-brown colouration is due to iron oxides and not algae as was originally thought. These iron compounds come from a lake under the Taylor Glacier where the unusual chemical profile of the lake water allows chemoautotrophic bacteria to survive without any sunlight or input of organic molecules from the outside. These bacteria take abundant Iron II ions (Fe²⁺) in the lake and oxidize them to Iron III ions (Fe³⁺) releasing energy in the process. This energy is used by the bacteria to synthesize complex organic molecules from simple ones in a manner similar to the way that plants use sunlight in photosynthesis.

Every now and then the lake water emerges from small cracks in the glacier giving rise to the "Blood Falls".

It is thought that this locked away simple bacterial ecosystem and others like it that do not need to derive energy from sunlight may indicate the existence of similar ecosystems elsewhere in the solar system such as Mars or ice covered moons such as Europa (a moon of Jupiter). It shows that subsurface liquid water can exist overlaid by thick ice which protects the water and anything in it from harmful high surface levels of ultraviolet light and cosmic rays while still being able to support life.

Blood Falls - Taylor Valley - Dry Valleys region Antarctica - the tent to the left gives a sense of scale

The top picture is a satellite image of the Dry Valleys area,
the bottom is a map of almost exactly the same area

 

Picture courtesy of Mike Usher - Mike went on a Ross Sea expedition on board the Kapitan Khlebnikov in 2005.
You can purchase a selection of Mike's pictures here