Sastrugi

Wednesday, 27th July 2005 by

Believe it or not, here’s something else to see in Antarctica! They are snow and ice dunes known as ‘sastrugi’, and are formed on a snow surface by wind erosion and deposition. They differ from sand dunes in that the ridges are parallel to the prevailing winds.

Sastrugi

These particular sastrugi are unusually large. NASAs Atmospheric Sciences Data Center says:

Usually sastrugi are only several centimeters high and several meters apart, but large portions of East Antarctica are covered by mega-sastrugi ice fields, with dune-like features as high as four meters separated by two to five kilometers. The mega sastrugi fields are a result of unusual snow accumulation and redistribution processes influenced by the prevailing winds and climate conditions. MISR imagery indicates that these mega sastrugi were stationary features between 2002 and 2004.

NASA has lots more information and a great image too, and although the pattern of dunes has changed, I believe you can still identify the exact region I’ve highlighted in our thumbnail. Cool.

Thanks to Twombly for letting us know what this was :-)