Extensive snow dunes wrinkle the surface of large parts of East and West Antarctica. The dunes are up to 100 kilometers long and separated by 2 to 4 kilometers, but only a few meters high. Comparison of modern satellite images with images acquired four decades earlier reveals that the dunes are nearly motionless. The dunes are unique in that they appear not to be formed by normal wind deposition, but rather by ablation due to wave patterns set up in katabatic winds. The linear pattern is due to backscatter variations associated with grain-size changes across dunes.
NOTE: White and/or blue colors used in the annotations are simply for better contrast against the background and have no other significance.