How are sand dunes formed and why do they even exist?

The strange, beautiful shapes that make up sand dunes are a mystery. Now researchers are doing huge desert experiments and using dune racing tracks to find out

Surroundings

November 11, 2020

By David Adam

The Capricorn Dunes in California’s Death Valley are stereotypical, shape-changing, wind-blown golden dunes

Alex Noriega

The Israeli city of Ashdod offers all the features of a modern metropolis. Shopping malls, theaters, night clubs, bars, lots of good schools. But there is something else. At least in normal times, citizens grab their buckets, spades and quads every weekend and head to the city’s most unexpected attraction: the world’s largest urban sandpit.

Ashdod’s Big Dune, up to 35 meters high and with a footprint of a dozen soccer fields, dominates the largely undeveloped district of City 14. As one of the last remnants of the region’s original coastal landscape, it’s not only a popular talk of the town, but also a dramatic one Example of a longstanding puzzle. As bizarre as it sounds, scientists aren’t sure how it got there – or why one of the world’s sand dunes exists.

On one level, the answer to this question is obvious: the wind blows individual grains of sand into heaps. But exactly how and why dunes form the way they form still escapes us. Now efforts to get to the bottom of it are taking on a new urgency, and not just because they could solve what Nathalie Vriend of Cambridge University declares to be a “fundamental physical problem.” As more and more human developments penetrate the desert area and parts of the world become drier due to climate change, it is time to better predict the paths of sand displacement.

The University of Cambridge Sand Dune Racetrack, which examines the underlying physics of these features

Karol …