Aeolian Landscape II

Observe a miniature wind-swept desert landscape that has been recreated by an electric fan and finely ground sand. “Aeolian Landscape II” mimics the process of wind picking up and depositing small particles. Geologists use the term aeolian to refer to land formations that are caused by wind — sand dunes and snow drifts are two common examples.

You can change the direction of the fan and notice how the shape of the miniature dunes influences the pattern of the wind, which in turn influences the shape of the dunes.

In order for a sand dune to form, not only does there have to be sand and wind, but something that will cause sand particles to lose their momentum and settle. Shrubs, rocks or fence posts can obstruct the wind causing sand to pile up in drifts and ultimately large dunes.

Something as small as an anthill can cause enough obstruction to start a sand dune. The wind moves individual grains along the inclined windward surface until they reach the crest and cascade down the steep leeward side, piling up at the base and slowly encroaching on new territory.

Questions to Ask

What over-all shape does each dune form when the fan is stationary for a period of time?

Is there a part of the dune that moves more slowly than the rest?

How high does a dune get before it rounds off across the top? Why do you think this happens?

Why aren’t aeolian deserts flat surfaces?

Relevant Arkansas Science Frameworks

ESS.8.k.1, ESS.8.1.1, (ESS.8.2.1, ESS.8.2.2), ESS.9.3.1, ESS.9.4.1, ESS.8.8.4, ESS.8.8.8, ESS.8.8.11

"Mini-Vibe" — An activity to do at home or in the classroom