[X] My Assistant

[volcanopele]

The latest issue of Science has hit the web, and it contains an article by Lorenz et al. on the Great dune seas of Titan, as seen in T8 RADAR data:

http://www.sciencemag.org/cgi/content/abstract/312/5774/724

The article characterizes the longitundinal dunes seen in the equatorial dark regions and compares them to those seen in the Namib desert in southwestern Africa.

[Thorsten]

So, longitudinal (seif) dunes on Titan are 100 – 150 m high and hundreds or thousands of km long with slopes of 6 – 10% and an average space from crest to crest of 2 – 3 km. Variable eastwards flowing surface winds of 0.5 km/s produce these dunes of 0.1 - 0.3 mm sized sand particles (slightly larger grain size than on Earth). Note that the image below shows a 5x vertical exaggeration.

For what its worth (probably it’s worth nothing at all), nomads of the Sahara desert – which have acquired an extensive vocabulary of sand dunes – call the crests of large longitudinal dunes Shnûf, while a large interspace between two dunes is called Aftût (a small one is called Gûwd) and a large longitudinal dune without crest is called Elb. Might be useful for future Titan explorers .

BTW, somebody wrote already an article about the sand dunes of Titan in the Wikipedia (Titan). Great work!

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