The difference is a matter of size: ripples are small ridges of sand with a height (amplitude) typically less than 4 cm and wave lengths (crest to crest) less than 60 cm, while dunes have the same ...

The wind is continuously moving sand grains up the longer dune slope, towards the top. The small ripples on the slope are caused by this movement. When the sand grains arrive at the top ...

A more than 40-mile long conveyor belt filled with sand stretches from the oil fields of West Texas to New Mexico, all for the purpose of one mission: oil production ...

The rolling dunes ripple across the majority of the park’s 1,550 sq km, and during certain times of year, natural rainwater pools can be found tucked between the waves of sand. These blue ...