The Dry Valleys area
in Antarctica is found to the West of McMurdo Sound in Victoria
Land. It consists of around 4800 square kilometres
(1850 square miles) of snow and ice free rock and gravel. It
is a unique area not only in Antarctica but also on the surface
of the earth in that it is intensely dry and intensely cold
without there being any liquid or frozen water in any
appreciable quantity at any time. The Dry Valleys are the closest
on earth to what the climate of Mars is like.
There are a number
of glaciers that flow into the Dry Valleys, but while some show
some melting and form seasonal lakes, streams and ponds, most
of the ice simply sublimes turning directly from solid to vapour
without a liquid stage. This happens due to the strong and almost
constant katabatic winds that blow through the valleys. These
winds can reach speeds of up to 320kmh (200 mph), sucking up
all moisture and also blowing sand around that carves rocks
into forms known as ventifacts.
Photo courtesy NASA
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
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