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 ...

This story appears in the November 2012 issue of National Geographic magazine. I got my first lesson in the physics of sand dunes in 1998 on an expedition into the Sahara. In order to take aerial ...

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 ...

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 ...

Police believe Sean Nagel was resting underneath a sand dune to film a sunrise when it collapsed on top of him Jason Hahn is a former Human Interest and Sports Reporter for PEOPLE. He started at ...

Appearances can be deceiving. At first glance, you'd never think the rolling white sand dunes of southeastern New Mexico and west Texas held the largest stand of oak in the country. The region's ...